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machine/atmega328pb: refactor to enable extra uart

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Этот коммит содержится в:
Yurii Soldak 2023-11-29 03:46:11 +01:00 • коммит произвёл Ron Evans
родитель 2d289addb7
коммит 6420e90124
10 изменённых файлов: 807 добавлений и 678 удалений
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2
GNUmakefile
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@ -718,6 +718,8 @@ ifneq ($(STM32), 0)
$(TINYGO) build -size short -o test.hex -target=swan examples/blinky1
@$(MD5SUM) test.hex
endif
$(TINYGO) build -size short -o test.hex -target=atmega328pb examples/blinkm
@$(MD5SUM) test.hex
$(TINYGO) build -size short -o test.hex -target=atmega1284p examples/serial
@$(MD5SUM) test.hex
$(TINYGO) build -size short -o test.hex -target=arduino examples/blinky1

5
src/machine/board_arduino.go
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@ -2,11 +2,6 @@
package machine
// Return the current CPU frequency in hertz.
func CPUFrequency() uint32 {
return 16000000
}
// Digital pins, marked as plain numbers on the board.
const (
D0 = PD0 // RX

5
src/machine/board_arduino_nano.go
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@ -2,11 +2,6 @@
package machine
// Return the current CPU frequency in hertz.
func CPUFrequency() uint32 {
return 16000000
}
// Digital pins.
const (
D0 = PD0 // RX0

5
src/machine/board_atmega328p.go
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@ -2,6 +2,11 @@
package machine
// Return the current CPU frequency in hertz.
func CPUFrequency() uint32 {
return 16000000
}
const (
// Note: start at port B because there is no port A.
portB Pin = iota * 8

51
src/machine/board_atmega328pb.go Обычный файл
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@ -0,0 +1,51 @@
//go:build avr && atmega328pb
package machine
// Return the current CPU frequency in hertz.
func CPUFrequency() uint32 {
return 16000000
}
const (
// Note: start at port B because there is no port A.
portB Pin = iota * 8
portC
portD
portE
)
const (
PB0 = portB + 0
PB1 = portB + 1 // peripherals: Timer1 channel A
PB2 = portB + 2 // peripherals: Timer1 channel B
PB3 = portB + 3 // peripherals: Timer2 channel A
PB4 = portB + 4
PB5 = portB + 5
PB6 = portB + 6
PB7 = portB + 7
PC0 = portC + 0
PC1 = portC + 1
PC2 = portC + 2
PC3 = portC + 3
PC4 = portC + 4
PC5 = portC + 5
PC6 = portC + 6
PC7 = portC + 7
PD0 = portD + 0
PD1 = portD + 1
PD2 = portD + 2
PD3 = portD + 3 // peripherals: Timer2 channel B
PD4 = portD + 4
PD5 = portD + 5 // peripherals: Timer0 channel B
PD6 = portD + 6 // peripherals: Timer0 channel A
PD7 = portD + 7
PE0 = portE + 0
PE1 = portE + 1
PE2 = portE + 2
PE3 = portE + 3
PE4 = portE + 4
PE5 = portE + 5
PE6 = portE + 6
PE7 = portE + 7
)

80
src/machine/machine_atmega.go
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@ -11,10 +11,19 @@ import (
// I2C on AVR.
type I2C struct {
}
srReg *volatile.Register8
brReg *volatile.Register8
crReg *volatile.Register8
drReg *volatile.Register8
// I2C0 is the only I2C interface on most AVRs.
var I2C0 *I2C = nil
srPS0 byte
srPS1 byte
crEN byte
crINT byte
crSTO byte
crEA byte
crSTA byte
}
// I2CConfig is used to store config info for I2C.
type I2CConfig struct {
@ -37,16 +46,16 @@ func (i2c *I2C) Configure(config I2CConfig) error {
// SetBaudRate sets the communication speed for I2C.
func (i2c *I2C) SetBaudRate(br uint32) error {
// Initialize twi prescaler and bit rate.
avr.TWSR.SetBits((avr.TWSR_TWPS0 | avr.TWSR_TWPS1))
i2c.srReg.SetBits((i2c.srPS0 | i2c.srPS1))
// twi bit rate formula from atmega128 manual pg. 204:
// SCL Frequency = CPU Clock Frequency / (16 + (2 * TWBR))
// NOTE: TWBR should be 10 or higher for controller mode.
// It is 72 for a 16mhz board with 100kHz TWI
avr.TWBR.Set(uint8(((CPUFrequency() / br) - 16) / 2))
i2c.brReg.Set(uint8(((CPUFrequency() / br) - 16) / 2))
// Enable twi module.
avr.TWCR.Set(avr.TWCR_TWEN)
i2c.crReg.Set(i2c.crEN)
return nil
}
@ -77,10 +86,10 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) error {
// start starts an I2C communication session.
func (i2c *I2C) start(address uint8, write bool) {
// Clear TWI interrupt flag, put start condition on SDA, and enable TWI.
avr.TWCR.Set((avr.TWCR_TWINT | avr.TWCR_TWSTA | avr.TWCR_TWEN))
i2c.crReg.Set((i2c.crINT | i2c.crSTA | i2c.crEN))
// Wait till start condition is transmitted.
for !avr.TWCR.HasBits(avr.TWCR_TWINT) {
for !i2c.crReg.HasBits(i2c.crINT) {
}
// Write 7-bit shifted peripheral address.
@ -94,23 +103,23 @@ func (i2c *I2C) start(address uint8, write bool) {
// stop ends an I2C communication session.
func (i2c *I2C) stop() {
// Send stop condition.
avr.TWCR.Set(avr.TWCR_TWEN | avr.TWCR_TWINT | avr.TWCR_TWSTO)
i2c.crReg.Set(i2c.crEN | i2c.crINT | i2c.crSTO)
// Wait for stop condition to be executed on bus.
for !avr.TWCR.HasBits(avr.TWCR_TWSTO) {
for !i2c.crReg.HasBits(i2c.crSTO) {
}
}
// writeByte writes a single byte to the I2C bus.
func (i2c *I2C) writeByte(data byte) error {
// Write data to register.
avr.TWDR.Set(data)
i2c.drReg.Set(data)
// Clear TWI interrupt flag and enable TWI.
avr.TWCR.Set(avr.TWCR_TWEN | avr.TWCR_TWINT)
i2c.crReg.Set(i2c.crEN | i2c.crINT)
// Wait till data is transmitted.
for !avr.TWCR.HasBits(avr.TWCR_TWINT) {
for !i2c.crReg.HasBits(i2c.crINT) {
}
return nil
}
@ -118,13 +127,13 @@ func (i2c *I2C) writeByte(data byte) error {
// readByte reads a single byte from the I2C bus.
func (i2c *I2C) readByte() byte {
// Clear TWI interrupt flag and enable TWI.
avr.TWCR.Set(avr.TWCR_TWEN | avr.TWCR_TWINT | avr.TWCR_TWEA)
i2c.crReg.Set(i2c.crEN | i2c.crINT | i2c.crEA)
// Wait till read request is transmitted.
for !avr.TWCR.HasBits(avr.TWCR_TWINT) {
for !i2c.crReg.HasBits(i2c.crINT) {
}
return byte(avr.TWDR.Get())
return byte(i2c.drReg.Get())
}
// Always use UART0 as the serial output.
@ -221,6 +230,17 @@ type SPI struct {
spdr *volatile.Register8
spsr *volatile.Register8
spcrR0 byte
spcrR1 byte
spcrCPHA byte
spcrCPOL byte
spcrDORD byte
spcrSPE byte
spcrMSTR byte
spsrI2X byte
spsrSPIF byte
// The io pins for the SPIx port set by the chip
sck Pin
sdi Pin
@ -264,39 +284,39 @@ func (s SPI) Configure(config SPIConfig) error {
switch {
case frequencyDivider >= 128:
s.spcr.SetBits(avr.SPCR_SPR0 | avr.SPCR_SPR1)
s.spcr.SetBits(s.spcrR0 | s.spcrR1)
case frequencyDivider >= 64:
s.spcr.SetBits(avr.SPCR_SPR1)
s.spcr.SetBits(s.spcrR1)
case frequencyDivider >= 32:
s.spcr.SetBits(avr.SPCR_SPR1)
s.spsr.SetBits(avr.SPSR_SPI2X)
s.spcr.SetBits(s.spcrR1)
s.spsr.SetBits(s.spsrI2X)
case frequencyDivider >= 16:
s.spcr.SetBits(avr.SPCR_SPR0)
s.spcr.SetBits(s.spcrR0)
case frequencyDivider >= 8:
s.spcr.SetBits(avr.SPCR_SPR0)
s.spsr.SetBits(avr.SPSR_SPI2X)
s.spcr.SetBits(s.spcrR0)
s.spsr.SetBits(s.spsrI2X)
case frequencyDivider >= 4:
// The clock is already set to all 0's.
default: // defaults to fastest which is /2
s.spsr.SetBits(avr.SPSR_SPI2X)
s.spsr.SetBits(s.spsrI2X)
}
switch config.Mode {
case Mode1:
s.spcr.SetBits(avr.SPCR_CPHA)
s.spcr.SetBits(s.spcrCPHA)
case Mode2:
s.spcr.SetBits(avr.SPCR_CPOL)
s.spcr.SetBits(s.spcrCPHA)
case Mode3:
s.spcr.SetBits(avr.SPCR_CPHA | avr.SPCR_CPOL)
s.spcr.SetBits(s.spcrCPHA | s.spcrCPOL)
default: // default is mode 0
}
if config.LSBFirst {
s.spcr.SetBits(avr.SPCR_DORD)
s.spcr.SetBits(s.spcrDORD)
}
// enable SPI, set controller, set clock rate
s.spcr.SetBits(avr.SPCR_SPE | avr.SPCR_MSTR)
s.spcr.SetBits(s.spcrSPE | s.spcrMSTR)
return nil
}
@ -305,7 +325,7 @@ func (s SPI) Configure(config SPIConfig) error {
func (s SPI) Transfer(b byte) (byte, error) {
s.spdr.Set(uint8(b))
for !s.spsr.HasBits(avr.SPSR_SPIF) {
for !s.spsr.HasBits(s.spsrSPIF) {
}
return byte(s.spdr.Get()), nil

548
src/machine/machine_atmega328.go Обычный файл
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@ -0,0 +1,548 @@
//go:build avr && (atmega328p || atmega328pb)
package machine
import (
"device/avr"
"runtime/interrupt"
"runtime/volatile"
)
// PWM is one PWM peripheral, which consists of a counter and two output
// channels (that can be connected to two fixed pins). You can set the frequency
// using SetPeriod, but only for all the channels in this PWM peripheral at
// once.
type PWM struct {
num uint8
}
var (
Timer0 = PWM{0} // 8 bit timer for PD5 and PD6
Timer1 = PWM{1} // 16 bit timer for PB1 and PB2
Timer2 = PWM{2} // 8 bit timer for PB3 and PD3
)
// Configure enables and configures this PWM.
//
// For the two 8 bit timers, there is only a limited number of periods
// available, namely the CPU frequency divided by 256 and again divided by 1, 8,
// 64, 256, or 1024. For a MCU running at 16MHz, this would be a period of 16µs,
// 128µs, 1024µs, 4096µs, or 16384µs.
func (pwm PWM) Configure(config PWMConfig) error {
switch pwm.num {
case 0, 2: // 8-bit timers (Timer/counter 0 and Timer/counter 2)
// Calculate the timer prescaler.
// While we could configure a flexible top, that would sacrifice one of
// the PWM output compare registers and thus a PWM channel. I've chosen
// to instead limit this timer to a fixed number of frequencies.
var prescaler uint8
switch config.Period {
case 0, (uint64(1e9) * 256 * 1) / uint64(CPUFrequency()):
prescaler = 1
case (uint64(1e9) * 256 * 8) / uint64(CPUFrequency()):
prescaler = 2
case (uint64(1e9) * 256 * 64) / uint64(CPUFrequency()):
prescaler = 3
case (uint64(1e9) * 256 * 256) / uint64(CPUFrequency()):
prescaler = 4
case (uint64(1e9) * 256 * 1024) / uint64(CPUFrequency()):
prescaler = 5
default:
return ErrPWMPeriodTooLong
}
if pwm.num == 0 {
avr.TCCR0B.Set(prescaler)
// Set the PWM mode to fast PWM (mode = 3).
avr.TCCR0A.Set(avr.TCCR0A_WGM00 | avr.TCCR0A_WGM01)
// monotonic timer is using the same time as PWM:0
// we must adust internal settings of monotonic timer when PWM:0 settings changed
adjustMonotonicTimer()
} else {
avr.TCCR2B.Set(prescaler)
// Set the PWM mode to fast PWM (mode = 3).
avr.TCCR2A.Set(avr.TCCR2A_WGM20 | avr.TCCR2A_WGM21)
}
case 1: // Timer/counter 1
// The top value is the number of PWM ticks a PWM period takes. It is
// initially picked assuming an unlimited counter top and no PWM
// prescaler.
var top uint64
if config.Period == 0 {
// Use a top appropriate for LEDs. Picking a relatively low period
// here (0xff) for consistency with the other timers.
top = 0xff
} else {
// The formula below calculates the following formula, optimized:
// top = period * (CPUFrequency() / 1e9)
// By dividing the CPU frequency first (an operation that is easily
// optimized away) the period has less chance of overflowing.
top = config.Period * (uint64(CPUFrequency()) / 1000000) / 1000
}
avr.TCCR1A.Set(avr.TCCR1A_WGM11)
// The ideal PWM period may be larger than would fit in the PWM counter,
// which is 16 bits (see maxTop). Therefore, try to make the PWM clock
// speed lower with a prescaler to make the top value fit the maximum
// top value.
const maxTop = 0x10000
switch {
case top <= maxTop:
avr.TCCR1B.Set(3<<3 | 1) // no prescaling
case top/8 <= maxTop:
avr.TCCR1B.Set(3<<3 | 2) // divide by 8
top /= 8
case top/64 <= maxTop:
avr.TCCR1B.Set(3<<3 | 3) // divide by 64
top /= 64
case top/256 <= maxTop:
avr.TCCR1B.Set(3<<3 | 4) // divide by 256
top /= 256
case top/1024 <= maxTop:
avr.TCCR1B.Set(3<<3 | 5) // divide by 1024
top /= 1024
default:
return ErrPWMPeriodTooLong
}
// A top of 0x10000 is at 100% duty cycle. Subtract one because the
// counter counts from 0, not 1 (avoiding an off-by-one).
top -= 1
avr.ICR1H.Set(uint8(top >> 8))
avr.ICR1L.Set(uint8(top))
}
return nil
}
// SetPeriod updates the period of this PWM peripheral.
// To set a particular frequency, use the following formula:
//
// period = 1e9 / frequency
//
// If you use a period of 0, a period that works well for LEDs will be picked.
//
// SetPeriod will not change the prescaler, but also won't change the current
// value in any of the channels. This means that you may need to update the
// value for the particular channel.
//
// Note that you cannot pick any arbitrary period after the PWM peripheral has
// been configured. If you want to switch between frequencies, pick the lowest
// frequency (longest period) once when calling Configure and adjust the
// frequency here as needed.
func (pwm PWM) SetPeriod(period uint64) error {
if pwm.num != 1 {
return ErrPWMPeriodTooLong // TODO better error message
}
// The top value is the number of PWM ticks a PWM period takes. It is
// initially picked assuming an unlimited counter top and no PWM
// prescaler.
var top uint64
if period == 0 {
// Use a top appropriate for LEDs. Picking a relatively low period
// here (0xff) for consistency with the other timers.
top = 0xff
} else {
// The formula below calculates the following formula, optimized:
// top = period * (CPUFrequency() / 1e9)
// By dividing the CPU frequency first (an operation that is easily
// optimized away) the period has less chance of overflowing.
top = period * (uint64(CPUFrequency()) / 1000000) / 1000
}
prescaler := avr.TCCR1B.Get() & 0x7
switch prescaler {
case 1:
top /= 1
case 2:
top /= 8
case 3:
top /= 64
case 4:
top /= 256
case 5:
top /= 1024
}
// A top of 0x10000 is at 100% duty cycle. Subtract one because the counter
// counts from 0, not 1 (avoiding an off-by-one).
top -= 1
if top > 0xffff {
return ErrPWMPeriodTooLong
}
// Warning: this change is not atomic!
avr.ICR1H.Set(uint8(top >> 8))
avr.ICR1L.Set(uint8(top))
// ... and because of that, set the counter back to zero to avoid most of
// the effects of this non-atomicity.
avr.TCNT1H.Set(0)
avr.TCNT1L.Set(0)
return nil
}
// Top returns the current counter top, for use in duty cycle calculation. It
// will only change with a call to Configure or SetPeriod, otherwise it is
// constant.
//
// The value returned here is hardware dependent. In general, it's best to treat
// it as an opaque value that can be divided by some number and passed to Set
// (see Set documentation for more information).
func (pwm PWM) Top() uint32 {
if pwm.num == 1 {
// Timer 1 has a configurable top value.
low := avr.ICR1L.Get()
high := avr.ICR1H.Get()
return uint32(high)<<8 | uint32(low) + 1
}
// Other timers go from 0 to 0xff (0x100 or 256 in total).
return 256
}
// Counter returns the current counter value of the timer in this PWM
// peripheral. It may be useful for debugging.
func (pwm PWM) Counter() uint32 {
switch pwm.num {
case 0:
return uint32(avr.TCNT0.Get())
case 1:
mask := interrupt.Disable()
low := avr.TCNT1L.Get()
high := avr.TCNT1H.Get()
interrupt.Restore(mask)
return uint32(high)<<8 | uint32(low)
case 2:
return uint32(avr.TCNT2.Get())
}
// Unknown PWM.
return 0
}
// Period returns the used PWM period in nanoseconds. It might deviate slightly
// from the configured period due to rounding.
func (pwm PWM) Period() uint64 {
var prescaler uint8
switch pwm.num {
case 0:
prescaler = avr.TCCR0B.Get() & 0x7
case 1:
prescaler = avr.TCCR1B.Get() & 0x7
case 2:
prescaler = avr.TCCR2B.Get() & 0x7
}
top := uint64(pwm.Top())
switch prescaler {
case 1: // prescaler 1
return 1 * top * 1000 / uint64(CPUFrequency()/1e6)
case 2: // prescaler 8
return 8 * top * 1000 / uint64(CPUFrequency()/1e6)
case 3: // prescaler 64
return 64 * top * 1000 / uint64(CPUFrequency()/1e6)
case 4: // prescaler 256
return 256 * top * 1000 / uint64(CPUFrequency()/1e6)
case 5: // prescaler 1024
return 1024 * top * 1000 / uint64(CPUFrequency()/1e6)
default: // unknown clock source
return 0
}
}
// Channel returns a PWM channel for the given pin.
func (pwm PWM) Channel(pin Pin) (uint8, error) {
pin.Configure(PinConfig{Mode: PinOutput})
pin.Low()
switch pwm.num {
case 0:
switch pin {
case PD6: // channel A
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A1)
return 0, nil
case PD5: // channel B
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B1)
return 1, nil
}
case 1:
switch pin {
case PB1: // channel A
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1)
return 0, nil
case PB2: // channel B
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1)
return 1, nil
}
case 2:
switch pin {
case PB3: // channel A
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A1)
return 0, nil
case PD3: // channel B
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B1)
return 1, nil
}
}
return 0, ErrInvalidOutputPin
}
// SetInverting sets whether to invert the output of this channel.
// Without inverting, a 25% duty cycle would mean the output is high for 25% of
// the time and low for the rest. Inverting flips the output as if a NOT gate
// was placed at the output, meaning that the output would be 25% low and 75%
// high with a duty cycle of 25%.
//
// Note: the invert state may not be applied on the AVR until the next call to
// ch.Set().
func (pwm PWM) SetInverting(channel uint8, inverting bool) {
switch pwm.num {
case 0:
switch channel {
case 0: // channel A
if inverting {
avr.PORTB.SetBits(1 << 6) // PB6 high
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A0)
} else {
avr.PORTB.ClearBits(1 << 6) // PB6 low
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0A0)
}
case 1: // channel B
if inverting {
avr.PORTB.SetBits(1 << 5) // PB5 high
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B0)
} else {
avr.PORTB.ClearBits(1 << 5) // PB5 low
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0B0)
}
}
case 1:
// Note: the COM1A0/COM1B0 bit is not set with the configuration below.
// It will be set the following call to Set(), however.
switch channel {
case 0: // channel A, PB1
if inverting {
avr.PORTB.SetBits(1 << 1) // PB1 high
} else {
avr.PORTB.ClearBits(1 << 1) // PB1 low
}
case 1: // channel B, PB2
if inverting {
avr.PORTB.SetBits(1 << 2) // PB2 high
} else {
avr.PORTB.ClearBits(1 << 2) // PB2 low
}
}
case 2:
switch channel {
case 0: // channel A
if inverting {
avr.PORTB.SetBits(1 << 3) // PB3 high
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A0)
} else {
avr.PORTB.ClearBits(1 << 3) // PB3 low
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2A0)
}
case 1: // channel B
if inverting {
avr.PORTD.SetBits(1 << 3) // PD3 high
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B0)
} else {
avr.PORTD.ClearBits(1 << 3) // PD3 low
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2B0)
}
}
}
}
// Set updates the channel value. This is used to control the channel duty
// cycle, in other words the fraction of time the channel output is high (or low
// when inverted). For example, to set it to a 25% duty cycle, use:
//
// pwm.Set(channel, pwm.Top() / 4)
//
// pwm.Set(channel, 0) will set the output to low and pwm.Set(channel,
// pwm.Top()) will set the output to high, assuming the output isn't inverted.
func (pwm PWM) Set(channel uint8, value uint32) {
switch pwm.num {
case 0:
value := uint16(value)
switch channel {
case 0: // channel A
if value == 0 {
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0A1)
} else {
avr.OCR0A.Set(uint8(value - 1))
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A1)
}
case 1: // channel B
if value == 0 {
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0B1)
} else {
avr.OCR0B.Set(uint8(value) - 1)
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B1)
}
}
// monotonic timer is using the same time as PWM:0
// we must adust internal settings of monotonic timer when PWM:0 settings changed
adjustMonotonicTimer()
case 1:
mask := interrupt.Disable()
switch channel {
case 0: // channel A, PB1
if value == 0 {
avr.TCCR1A.ClearBits(avr.TCCR1A_COM1A1 | avr.TCCR1A_COM1A0)
} else {
value := uint16(value) - 1 // yes, this is safe (it relies on underflow)
avr.OCR1AH.Set(uint8(value >> 8))
avr.OCR1AL.Set(uint8(value))
if avr.PORTB.HasBits(1 << 1) { // is PB1 high?
// Yes, set the inverting bit.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1 | avr.TCCR1A_COM1A0)
} else {
// No, output is non-inverting.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1)
}
}
case 1: // channel B, PB2
if value == 0 {
avr.TCCR1A.ClearBits(avr.TCCR1A_COM1B1 | avr.TCCR1A_COM1B0)
} else {
value := uint16(value) - 1 // yes, this is safe (it relies on underflow)
avr.OCR1BH.Set(uint8(value >> 8))
avr.OCR1BL.Set(uint8(value))
if avr.PORTB.HasBits(1 << 2) { // is PB2 high?
// Yes, set the inverting bit.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1 | avr.TCCR1A_COM1B0)
} else {
// No, output is non-inverting.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1)
}
}
}
interrupt.Restore(mask)
case 2:
value := uint16(value)
switch channel {
case 0: // channel A
if value == 0 {
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2A1)
} else {
avr.OCR2A.Set(uint8(value - 1))
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A1)
}
case 1: // channel B
if value == 0 {
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2B1)
} else {
avr.OCR2B.Set(uint8(value - 1))
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B1)
}
}
}
}
// Pin Change Interrupts
type PinChange uint8
const (
PinRising PinChange = 1 << iota
PinFalling
PinToggle = PinRising | PinFalling
)
func (pin Pin) SetInterrupt(pinChange PinChange, callback func(Pin)) (err error) {
switch {
case pin >= PB0 && pin <= PB7:
// PCMSK0 - PCINT0-7
pinStates[0] = avr.PINB.Get()
pinIndex := pin - PB0
if pinChange&PinRising > 0 {
pinCallbacks[0][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[0][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK0.SetBits(1 << pinIndex)
} else {
avr.PCMSK0.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE0)
interrupt.New(avr.IRQ_PCINT0, handlePCINT0Interrupts)
case pin >= PC0 && pin <= PC7:
// PCMSK1 - PCINT8-14
pinStates[1] = avr.PINC.Get()
pinIndex := pin - PC0
if pinChange&PinRising > 0 {
pinCallbacks[1][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[1][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK1.SetBits(1 << pinIndex)
} else {
avr.PCMSK1.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE1)
interrupt.New(avr.IRQ_PCINT1, handlePCINT1Interrupts)
case pin >= PD0 && pin <= PD7:
// PCMSK2 - PCINT16-23
pinStates[2] = avr.PIND.Get()
pinIndex := pin - PD0
if pinChange&PinRising > 0 {
pinCallbacks[2][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[2][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK2.SetBits(1 << pinIndex)
} else {
avr.PCMSK2.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE2)
interrupt.New(avr.IRQ_PCINT2, handlePCINT2Interrupts)
default:
return ErrInvalidInputPin
}
return nil
}
var pinCallbacks [3][8][2]func(Pin)
var pinStates [3]uint8
func handlePCINTInterrupts(intr uint8, port *volatile.Register8) {
current := port.Get()
change := pinStates[intr] ^ current
pinStates[intr] = current
for i := uint8(0); i < 8; i++ {
if (change>>i)&0x01 != 0x01 {
continue
}
pin := Pin(intr*8 + i)
value := pin.Get()
if value && pinCallbacks[intr][i][0] != nil {
pinCallbacks[intr][i][0](pin)
}
if !value && pinCallbacks[intr][i][1] != nil {
pinCallbacks[intr][i][1](pin)
}
}
}
func handlePCINT0Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(0, avr.PINB)
}
func handlePCINT1Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(1, avr.PINC)
}
func handlePCINT2Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(2, avr.PIND)
}

588
src/machine/machine_atmega328p.go
Просмотреть файл

@ -4,12 +4,49 @@ package machine
import (
"device/avr"
"runtime/interrupt"
"runtime/volatile"
)
const irq_USART0_RX = avr.IRQ_USART_RX
// I2C0 is the only I2C interface on most AVRs.
var I2C0 = &I2C{
srReg: avr.TWSR,
brReg: avr.TWBR,
crReg: avr.TWCR,
drReg: avr.TWDR,
srPS0: avr.TWSR_TWPS0,
srPS1: avr.TWSR_TWPS1,
crEN: avr.TWCR_TWEN,
crINT: avr.TWCR_TWINT,
crSTO: avr.TWCR_TWSTO,
crEA: avr.TWCR_TWEA,
crSTA: avr.TWCR_TWSTA,
}
// SPI configuration
var SPI0 = SPI{
spcr: avr.SPCR,
spdr: avr.SPDR,
spsr: avr.SPSR,
spcrR0: avr.SPCR_SPR0,
spcrR1: avr.SPCR_SPR1,
spcrCPHA: avr.SPCR_CPHA,
spcrCPOL: avr.SPCR_CPOL,
spcrDORD: avr.SPCR_DORD,
spcrSPE: avr.SPCR_SPE,
spcrMSTR: avr.SPCR_MSTR,
spsrI2X: avr.SPSR_SPI2X,
spsrSPIF: avr.SPSR_SPIF,
sck: PB5,
sdo: PB3,
sdi: PB4,
cs: PB2,
}
// getPortMask returns the PORTx register and mask for the pin.
func (p Pin) getPortMask() (*volatile.Register8, uint8) {
switch {
@ -21,552 +58,3 @@ func (p Pin) getPortMask() (*volatile.Register8, uint8) {
return avr.PORTD, 1 << uint8(p-portD)
}
}
// PWM is one PWM peripheral, which consists of a counter and two output
// channels (that can be connected to two fixed pins). You can set the frequency
// using SetPeriod, but only for all the channels in this PWM peripheral at
// once.
type PWM struct {
num uint8
}
var (
Timer0 = PWM{0} // 8 bit timer for PD5 and PD6
Timer1 = PWM{1} // 16 bit timer for PB1 and PB2
Timer2 = PWM{2} // 8 bit timer for PB3 and PD3
)
// Configure enables and configures this PWM.
//
// For the two 8 bit timers, there is only a limited number of periods
// available, namely the CPU frequency divided by 256 and again divided by 1, 8,
// 64, 256, or 1024. For a MCU running at 16MHz, this would be a period of 16µs,
// 128µs, 1024µs, 4096µs, or 16384µs.
func (pwm PWM) Configure(config PWMConfig) error {
switch pwm.num {
case 0, 2: // 8-bit timers (Timer/counter 0 and Timer/counter 2)
// Calculate the timer prescaler.
// While we could configure a flexible top, that would sacrifice one of
// the PWM output compare registers and thus a PWM channel. I've chosen
// to instead limit this timer to a fixed number of frequencies.
var prescaler uint8
switch config.Period {
case 0, (uint64(1e9) * 256 * 1) / uint64(CPUFrequency()):
prescaler = 1
case (uint64(1e9) * 256 * 8) / uint64(CPUFrequency()):
prescaler = 2
case (uint64(1e9) * 256 * 64) / uint64(CPUFrequency()):
prescaler = 3
case (uint64(1e9) * 256 * 256) / uint64(CPUFrequency()):
prescaler = 4
case (uint64(1e9) * 256 * 1024) / uint64(CPUFrequency()):
prescaler = 5
default:
return ErrPWMPeriodTooLong
}
if pwm.num == 0 {
avr.TCCR0B.Set(prescaler)
// Set the PWM mode to fast PWM (mode = 3).
avr.TCCR0A.Set(avr.TCCR0A_WGM00 | avr.TCCR0A_WGM01)
// monotonic timer is using the same time as PWM:0
// we must adust internal settings of monotonic timer when PWM:0 settings changed
adjustMonotonicTimer()
} else {
avr.TCCR2B.Set(prescaler)
// Set the PWM mode to fast PWM (mode = 3).
avr.TCCR2A.Set(avr.TCCR2A_WGM20 | avr.TCCR2A_WGM21)
}
case 1: // Timer/counter 1
// The top value is the number of PWM ticks a PWM period takes. It is
// initially picked assuming an unlimited counter top and no PWM
// prescaler.
var top uint64
if config.Period == 0 {
// Use a top appropriate for LEDs. Picking a relatively low period
// here (0xff) for consistency with the other timers.
top = 0xff
} else {
// The formula below calculates the following formula, optimized:
// top = period * (CPUFrequency() / 1e9)
// By dividing the CPU frequency first (an operation that is easily
// optimized away) the period has less chance of overflowing.
top = config.Period * (uint64(CPUFrequency()) / 1000000) / 1000
}
avr.TCCR1A.Set(avr.TCCR1A_WGM11)
// The ideal PWM period may be larger than would fit in the PWM counter,
// which is 16 bits (see maxTop). Therefore, try to make the PWM clock
// speed lower with a prescaler to make the top value fit the maximum
// top value.
const maxTop = 0x10000
switch {
case top <= maxTop:
avr.TCCR1B.Set(3<<3 | 1) // no prescaling
case top/8 <= maxTop:
avr.TCCR1B.Set(3<<3 | 2) // divide by 8
top /= 8
case top/64 <= maxTop:
avr.TCCR1B.Set(3<<3 | 3) // divide by 64
top /= 64
case top/256 <= maxTop:
avr.TCCR1B.Set(3<<3 | 4) // divide by 256
top /= 256
case top/1024 <= maxTop:
avr.TCCR1B.Set(3<<3 | 5) // divide by 1024
top /= 1024
default:
return ErrPWMPeriodTooLong
}
// A top of 0x10000 is at 100% duty cycle. Subtract one because the
// counter counts from 0, not 1 (avoiding an off-by-one).
top -= 1
avr.ICR1H.Set(uint8(top >> 8))
avr.ICR1L.Set(uint8(top))
}
return nil
}
// SetPeriod updates the period of this PWM peripheral.
// To set a particular frequency, use the following formula:
//
// period = 1e9 / frequency
//
// If you use a period of 0, a period that works well for LEDs will be picked.
//
// SetPeriod will not change the prescaler, but also won't change the current
// value in any of the channels. This means that you may need to update the
// value for the particular channel.
//
// Note that you cannot pick any arbitrary period after the PWM peripheral has
// been configured. If you want to switch between frequencies, pick the lowest
// frequency (longest period) once when calling Configure and adjust the
// frequency here as needed.
func (pwm PWM) SetPeriod(period uint64) error {
if pwm.num != 1 {
return ErrPWMPeriodTooLong // TODO better error message
}
// The top value is the number of PWM ticks a PWM period takes. It is
// initially picked assuming an unlimited counter top and no PWM
// prescaler.
var top uint64
if period == 0 {
// Use a top appropriate for LEDs. Picking a relatively low period
// here (0xff) for consistency with the other timers.
top = 0xff
} else {
// The formula below calculates the following formula, optimized:
// top = period * (CPUFrequency() / 1e9)
// By dividing the CPU frequency first (an operation that is easily
// optimized away) the period has less chance of overflowing.
top = period * (uint64(CPUFrequency()) / 1000000) / 1000
}
prescaler := avr.TCCR1B.Get() & 0x7
switch prescaler {
case 1:
top /= 1
case 2:
top /= 8
case 3:
top /= 64
case 4:
top /= 256
case 5:
top /= 1024
}
// A top of 0x10000 is at 100% duty cycle. Subtract one because the counter
// counts from 0, not 1 (avoiding an off-by-one).
top -= 1
if top > 0xffff {
return ErrPWMPeriodTooLong
}
// Warning: this change is not atomic!
avr.ICR1H.Set(uint8(top >> 8))
avr.ICR1L.Set(uint8(top))
// ... and because of that, set the counter back to zero to avoid most of
// the effects of this non-atomicity.
avr.TCNT1H.Set(0)
avr.TCNT1L.Set(0)
return nil
}
// Top returns the current counter top, for use in duty cycle calculation. It
// will only change with a call to Configure or SetPeriod, otherwise it is
// constant.
//
// The value returned here is hardware dependent. In general, it's best to treat
// it as an opaque value that can be divided by some number and passed to Set
// (see Set documentation for more information).
func (pwm PWM) Top() uint32 {
if pwm.num == 1 {
// Timer 1 has a configurable top value.
low := avr.ICR1L.Get()
high := avr.ICR1H.Get()
return uint32(high)<<8 | uint32(low) + 1
}
// Other timers go from 0 to 0xff (0x100 or 256 in total).
return 256
}
// Counter returns the current counter value of the timer in this PWM
// peripheral. It may be useful for debugging.
func (pwm PWM) Counter() uint32 {
switch pwm.num {
case 0:
return uint32(avr.TCNT0.Get())
case 1:
mask := interrupt.Disable()
low := avr.TCNT1L.Get()
high := avr.TCNT1H.Get()
interrupt.Restore(mask)
return uint32(high)<<8 | uint32(low)
case 2:
return uint32(avr.TCNT2.Get())
}
// Unknown PWM.
return 0
}
// Period returns the used PWM period in nanoseconds. It might deviate slightly
// from the configured period due to rounding.
func (pwm PWM) Period() uint64 {
var prescaler uint8
switch pwm.num {
case 0:
prescaler = avr.TCCR0B.Get() & 0x7
case 1:
prescaler = avr.TCCR1B.Get() & 0x7
case 2:
prescaler = avr.TCCR2B.Get() & 0x7
}
top := uint64(pwm.Top())
switch prescaler {
case 1: // prescaler 1
return 1 * top * 1000 / uint64(CPUFrequency()/1e6)
case 2: // prescaler 8
return 8 * top * 1000 / uint64(CPUFrequency()/1e6)
case 3: // prescaler 64
return 64 * top * 1000 / uint64(CPUFrequency()/1e6)
case 4: // prescaler 256
return 256 * top * 1000 / uint64(CPUFrequency()/1e6)
case 5: // prescaler 1024
return 1024 * top * 1000 / uint64(CPUFrequency()/1e6)
default: // unknown clock source
return 0
}
}
// Channel returns a PWM channel for the given pin.
func (pwm PWM) Channel(pin Pin) (uint8, error) {
pin.Configure(PinConfig{Mode: PinOutput})
pin.Low()
switch pwm.num {
case 0:
switch pin {
case PD6: // channel A
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A1)
return 0, nil
case PD5: // channel B
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B1)
return 1, nil
}
case 1:
switch pin {
case PB1: // channel A
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1)
return 0, nil
case PB2: // channel B
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1)
return 1, nil
}
case 2:
switch pin {
case PB3: // channel A
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A1)
return 0, nil
case PD3: // channel B
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B1)
return 1, nil
}
}
return 0, ErrInvalidOutputPin
}
// SetInverting sets whether to invert the output of this channel.
// Without inverting, a 25% duty cycle would mean the output is high for 25% of
// the time and low for the rest. Inverting flips the output as if a NOT gate
// was placed at the output, meaning that the output would be 25% low and 75%
// high with a duty cycle of 25%.
//
// Note: the invert state may not be applied on the AVR until the next call to
// ch.Set().
func (pwm PWM) SetInverting(channel uint8, inverting bool) {
switch pwm.num {
case 0:
switch channel {
case 0: // channel A
if inverting {
avr.PORTB.SetBits(1 << 6) // PB6 high
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A0)
} else {
avr.PORTB.ClearBits(1 << 6) // PB6 low
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0A0)
}
case 1: // channel B
if inverting {
avr.PORTB.SetBits(1 << 5) // PB5 high
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B0)
} else {
avr.PORTB.ClearBits(1 << 5) // PB5 low
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0B0)
}
}
case 1:
// Note: the COM1A0/COM1B0 bit is not set with the configuration below.
// It will be set the following call to Set(), however.
switch channel {
case 0: // channel A, PB1
if inverting {
avr.PORTB.SetBits(1 << 1) // PB1 high
} else {
avr.PORTB.ClearBits(1 << 1) // PB1 low
}
case 1: // channel B, PB2
if inverting {
avr.PORTB.SetBits(1 << 2) // PB2 high
} else {
avr.PORTB.ClearBits(1 << 2) // PB2 low
}
}
case 2:
switch channel {
case 0: // channel A
if inverting {
avr.PORTB.SetBits(1 << 3) // PB3 high
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A0)
} else {
avr.PORTB.ClearBits(1 << 3) // PB3 low
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2A0)
}
case 1: // channel B
if inverting {
avr.PORTD.SetBits(1 << 3) // PD3 high
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B0)
} else {
avr.PORTD.ClearBits(1 << 3) // PD3 low
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2B0)
}
}
}
}
// Set updates the channel value. This is used to control the channel duty
// cycle, in other words the fraction of time the channel output is high (or low
// when inverted). For example, to set it to a 25% duty cycle, use:
//
// pwm.Set(channel, pwm.Top() / 4)
//
// pwm.Set(channel, 0) will set the output to low and pwm.Set(channel,
// pwm.Top()) will set the output to high, assuming the output isn't inverted.
func (pwm PWM) Set(channel uint8, value uint32) {
switch pwm.num {
case 0:
value := uint16(value)
switch channel {
case 0: // channel A
if value == 0 {
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0A1)
} else {
avr.OCR0A.Set(uint8(value - 1))
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A1)
}
case 1: // channel B
if value == 0 {
avr.TCCR0A.ClearBits(avr.TCCR0A_COM0B1)
} else {
avr.OCR0B.Set(uint8(value) - 1)
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B1)
}
}
// monotonic timer is using the same time as PWM:0
// we must adust internal settings of monotonic timer when PWM:0 settings changed
adjustMonotonicTimer()
case 1:
mask := interrupt.Disable()
switch channel {
case 0: // channel A, PB1
if value == 0 {
avr.TCCR1A.ClearBits(avr.TCCR1A_COM1A1 | avr.TCCR1A_COM1A0)
} else {
value := uint16(value) - 1 // yes, this is safe (it relies on underflow)
avr.OCR1AH.Set(uint8(value >> 8))
avr.OCR1AL.Set(uint8(value))
if avr.PORTB.HasBits(1 << 1) { // is PB1 high?
// Yes, set the inverting bit.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1 | avr.TCCR1A_COM1A0)
} else {
// No, output is non-inverting.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1)
}
}
case 1: // channel B, PB2
if value == 0 {
avr.TCCR1A.ClearBits(avr.TCCR1A_COM1B1 | avr.TCCR1A_COM1B0)
} else {
value := uint16(value) - 1 // yes, this is safe (it relies on underflow)
avr.OCR1BH.Set(uint8(value >> 8))
avr.OCR1BL.Set(uint8(value))
if avr.PORTB.HasBits(1 << 2) { // is PB2 high?
// Yes, set the inverting bit.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1 | avr.TCCR1A_COM1B0)
} else {
// No, output is non-inverting.
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1)
}
}
}
interrupt.Restore(mask)
case 2:
value := uint16(value)
switch channel {
case 0: // channel A
if value == 0 {
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2A1)
} else {
avr.OCR2A.Set(uint8(value - 1))
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A1)
}
case 1: // channel B
if value == 0 {
avr.TCCR2A.ClearBits(avr.TCCR2A_COM2B1)
} else {
avr.OCR2B.Set(uint8(value - 1))
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B1)
}
}
}
}
// SPI configuration
var SPI0 = SPI{
spcr: avr.SPCR,
spdr: avr.SPDR,
spsr: avr.SPSR,
sck: PB5,
sdo: PB3,
sdi: PB4,
cs: PB2}
// Pin Change Interrupts
type PinChange uint8
const (
PinRising PinChange = 1 << iota
PinFalling
PinToggle = PinRising | PinFalling
)
func (pin Pin) SetInterrupt(pinChange PinChange, callback func(Pin)) (err error) {
switch {
case pin >= PB0 && pin <= PB7:
// PCMSK0 - PCINT0-7
pinStates[0] = avr.PINB.Get()
pinIndex := pin - PB0
if pinChange&PinRising > 0 {
pinCallbacks[0][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[0][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK0.SetBits(1 << pinIndex)
} else {
avr.PCMSK0.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE0)
interrupt.New(avr.IRQ_PCINT0, handlePCINT0Interrupts)
case pin >= PC0 && pin <= PC7:
// PCMSK1 - PCINT8-14
pinStates[1] = avr.PINC.Get()
pinIndex := pin - PC0
if pinChange&PinRising > 0 {
pinCallbacks[1][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[1][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK1.SetBits(1 << pinIndex)
} else {
avr.PCMSK1.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE1)
interrupt.New(avr.IRQ_PCINT1, handlePCINT1Interrupts)
case pin >= PD0 && pin <= PD7:
// PCMSK2 - PCINT16-23
pinStates[2] = avr.PIND.Get()
pinIndex := pin - PD0
if pinChange&PinRising > 0 {
pinCallbacks[2][pinIndex][0] = callback
}
if pinChange&PinFalling > 0 {
pinCallbacks[2][pinIndex][1] = callback
}
if callback != nil {
avr.PCMSK2.SetBits(1 << pinIndex)
} else {
avr.PCMSK2.ClearBits(1 << pinIndex)
}
avr.PCICR.SetBits(avr.PCICR_PCIE2)
interrupt.New(avr.IRQ_PCINT2, handlePCINT2Interrupts)
default:
return ErrInvalidInputPin
}
return nil
}
var pinCallbacks [3][8][2]func(Pin)
var pinStates [3]uint8
func handlePCINTInterrupts(intr uint8, port *volatile.Register8) {
current := port.Get()
change := pinStates[intr] ^ current
pinStates[intr] = current
for i := uint8(0); i < 8; i++ {
if (change>>i)&0x01 != 0x01 {
continue
}
pin := Pin(intr*8 + i)
value := pin.Get()
if value && pinCallbacks[intr][i][0] != nil {
pinCallbacks[intr][i][0](pin)
}
if !value && pinCallbacks[intr][i][1] != nil {
pinCallbacks[intr][i][1](pin)
}
}
}
func handlePCINT0Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(0, avr.PINB)
}
func handlePCINT1Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(1, avr.PINC)
}
func handlePCINT2Interrupts(intr interrupt.Interrupt) {
handlePCINTInterrupts(2, avr.PIND)
}

186
src/machine/machine_atmega328pb.go
Просмотреть файл

@ -4,10 +4,105 @@ package machine
import (
"device/avr"
"runtime/interrupt"
"runtime/volatile"
)
const irq_USART0_RX = avr.IRQ_USART0_RX
const irq_USART1_RX = avr.IRQ_USART1_RX
var (
UART1 = &_UART1
_UART1 = UART{
Buffer: NewRingBuffer(),
dataReg: avr.UDR1,
baudRegH: avr.UBRR1H,
baudRegL: avr.UBRR1L,
statusRegA: avr.UCSR1A,
statusRegB: avr.UCSR1B,
statusRegC: avr.UCSR1C,
}
)
func init() {
// Register the UART interrupt.
interrupt.New(irq_USART1_RX, _UART1.handleInterrupt)
}
// I2C0 is the only I2C interface on most AVRs.
var I2C0 = &I2C{
srReg: avr.TWSR0,
brReg: avr.TWBR0,
crReg: avr.TWCR0,
drReg: avr.TWDR0,
srPS0: avr.TWSR0_TWPS0,
srPS1: avr.TWSR0_TWPS1,
crEN: avr.TWCR0_TWEN,
crINT: avr.TWCR0_TWINT,
crSTO: avr.TWCR0_TWSTO,
crEA: avr.TWCR0_TWEA,
crSTA: avr.TWCR0_TWSTA,
}
var I2C1 = &I2C{
srReg: avr.TWSR1,
brReg: avr.TWBR1,
crReg: avr.TWCR1,
drReg: avr.TWDR1,
srPS0: avr.TWSR1_TWPS10,
srPS1: avr.TWSR1_TWPS11,
crEN: avr.TWCR1_TWEN1,
crINT: avr.TWCR1_TWINT1,
crSTO: avr.TWCR1_TWSTO1,
crEA: avr.TWCR1_TWEA1,
crSTA: avr.TWCR1_TWSTA1,
}
// SPI configuration
var SPI0 = SPI{
spcr: avr.SPCR0,
spdr: avr.SPDR0,
spsr: avr.SPSR0,
spcrR0: avr.SPCR0_SPR0,
spcrR1: avr.SPCR0_SPR1,
spcrCPHA: avr.SPCR0_CPHA,
spcrCPOL: avr.SPCR0_CPOL,
spcrDORD: avr.SPCR0_DORD,
spcrSPE: avr.SPCR0_SPE,
spcrMSTR: avr.SPCR0_MSTR,
spsrI2X: avr.SPSR0_SPI2X,
spsrSPIF: avr.SPSR0_SPIF,
sck: PB5,
sdo: PB3,
sdi: PB4,
cs: PB2,
}
var SPI1 = SPI{
spcr: avr.SPCR1,
spdr: avr.SPDR1,
spsr: avr.SPSR1,
spcrR0: avr.SPCR1_SPR10,
spcrR1: avr.SPCR1_SPR11,
spcrCPHA: avr.SPCR1_CPHA1,
spcrCPOL: avr.SPCR1_CPOL1,
spcrDORD: avr.SPCR1_DORD1,
spcrSPE: avr.SPCR1_SPE1,
spcrMSTR: avr.SPCR1_MSTR1,
spsrI2X: avr.SPSR1_SPI2X1,
spsrSPIF: avr.SPSR1_SPIF1,
sck: PC1,
sdo: PE3,
sdi: PC0,
cs: PE2,
}
// getPortMask returns the PORTx register and mask for the pin.
func (p Pin) getPortMask() (*volatile.Register8, uint8) {
@ -16,94 +111,9 @@ func (p Pin) getPortMask() (*volatile.Register8, uint8) {
return avr.PORTB, 1 << uint8(p-portB)
case p >= PC0 && p <= PC7: // port C
return avr.PORTC, 1 << uint8(p-portC)
default: // port D
case p >= PD0 && p <= PD7: // port D
return avr.PORTD, 1 << uint8(p-portD)
default: // port E
return avr.PORTE, 1 << uint8(p-portE)
}
}
// InitPWM initializes the registers needed for PWM.
func InitPWM() {
// use waveform generation
avr.TCCR0A.SetBits(avr.TCCR0A_WGM00)
// set timer 0 prescale factor to 64
avr.TCCR0B.SetBits(avr.TCCR0B_CS01 | avr.TCCR0B_CS00)
// set timer 1 prescale factor to 64
avr.TCCR1B.SetBits(avr.TCCR1B_CS11)
// put timer 1 in 8-bit phase correct pwm mode
avr.TCCR1A.SetBits(avr.TCCR1A_WGM10)
// set timer 2 prescale factor to 64
avr.TCCR2B.SetBits(avr.TCCR2B_CS22)
// configure timer 2 for phase correct pwm (8-bit)
avr.TCCR2A.SetBits(avr.TCCR2A_WGM20)
}
// Configure configures a PWM pin for output.
func (pwm PWM) Configure() error {
switch pwm.Pin / 8 {
case 0: // port B
avr.DDRB.SetBits(1 << uint8(pwm.Pin))
case 2: // port D
avr.DDRD.SetBits(1 << uint8(pwm.Pin-16))
}
return nil
}
// Set turns on the duty cycle for a PWM pin using the provided value. On the AVR this is normally a
// 8-bit value ranging from 0 to 255.
func (pwm PWM) Set(value uint16) {
value8 := uint8(value >> 8)
switch pwm.Pin {
case PD3:
// connect pwm to pin on timer 2, channel B
avr.TCCR2A.SetBits(avr.TCCR2A_COM2B1)
avr.OCR2B.Set(value8) // set pwm duty
case PD5:
// connect pwm to pin on timer 0, channel B
avr.TCCR0A.SetBits(avr.TCCR0A_COM0B1)
avr.OCR0B.Set(value8) // set pwm duty
case PD6:
// connect pwm to pin on timer 0, channel A
avr.TCCR0A.SetBits(avr.TCCR0A_COM0A1)
avr.OCR0A.Set(value8) // set pwm duty
case PB1:
// connect pwm to pin on timer 1, channel A
avr.TCCR1A.SetBits(avr.TCCR1A_COM1A1)
// this is a 16-bit value, but we only currently allow the low order bits to be set
avr.OCR1AL.Set(value8) // set pwm duty
case PB2:
// connect pwm to pin on timer 1, channel B
avr.TCCR1A.SetBits(avr.TCCR1A_COM1B1)
// this is a 16-bit value, but we only currently allow the low order bits to be set
avr.OCR1BL.Set(value8) // set pwm duty
case PB3:
// connect pwm to pin on timer 2, channel A
avr.TCCR2A.SetBits(avr.TCCR2A_COM2A1)
avr.OCR2A.Set(value8) // set pwm duty
default:
panic("Invalid PWM pin")
}
}
// SPI configuration
var SPI0 = SPI{
spcr: avr.SPCR0,
spdr: avr.SPDR0,
spsr: avr.SPSR0,
sck: PB5,
sdo: PB3,
sdi: PB4,
cs: PB2}
var SPI1 = SPI{
spcr: avr.SPCR1,
spdr: avr.SPDR1,
spsr: avr.SPSR1,
sck: PC1,
sdo: PE3,
sdi: PC0,
cs: PE2}

15
targets/atmega328pb.json Обычный файл
Просмотреть файл

@ -0,0 +1,15 @@
{
"inherits": ["avr"],
"cpu": "atmega328pb",
"build-tags": ["atmega328pb", "atmega", "avr5"],
"ldflags": [
"--defsym=_bootloader_size=512",
"--defsym=_stack_size=512"
],
"serial": "uart",
"linkerscript": "src/device/avr/atmega328pb.ld",
"extra-files": [
"targets/avr.S",
"src/device/avr/atmega328pb.s"
]
}