diff options
Diffstat (limited to 'src/machine/machine_rp2040_pwm.go')
| -rw-r--r-- | src/machine/machine_rp2040_pwm.go | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/src/machine/machine_rp2040_pwm.go b/src/machine/machine_rp2040_pwm.go index a355be4c8..330968a6a 100644 --- a/src/machine/machine_rp2040_pwm.go +++ b/src/machine/machine_rp2040_pwm.go @@ -45,8 +45,10 @@ type pwmGroup struct { } // Equivalent of -// var pwmSlice []pwmGroup = (*[8]pwmGroup)(unsafe.Pointer(rp.PWM))[:] -// return &pwmSlice[index] +// +// var pwmSlice []pwmGroup = (*[8]pwmGroup)(unsafe.Pointer(rp.PWM))[:] +// return &pwmSlice[index] +// // 0x14 is the size of a pwmGroup. func getPWMGroup(index uintptr) *pwmGroup { return (*pwmGroup)(unsafe.Pointer(uintptr(unsafe.Pointer(rp.PWM)) + 0x14*index)) @@ -112,7 +114,7 @@ func (pwm *pwmGroup) peripheral() uint8 { // SetPeriod updates the period of this PWM peripheral in nanoseconds. // To set a particular frequency, use the following formula: // -// period = 1e9 / frequency +// period = 1e9 / frequency // // Where frequency is in hertz. If you use a period of 0, a period // that works well for LEDs will be picked. @@ -167,7 +169,7 @@ func (p *pwmGroup) SetInverting(channel uint8, inverting bool) { // 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, 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. @@ -238,14 +240,17 @@ func (pwm *pwmGroup) setPhaseCorrect(correct bool) { } // Takes any of the following: -// rp.PWM_CH0_CSR_DIVMODE_DIV, rp.PWM_CH0_CSR_DIVMODE_FALL, -// rp.PWM_CH0_CSR_DIVMODE_LEVEL, rp.PWM_CH0_CSR_DIVMODE_RISE +// +// rp.PWM_CH0_CSR_DIVMODE_DIV, rp.PWM_CH0_CSR_DIVMODE_FALL, +// rp.PWM_CH0_CSR_DIVMODE_LEVEL, rp.PWM_CH0_CSR_DIVMODE_RISE func (pwm *pwmGroup) setDivMode(mode uint32) { pwm.CSR.ReplaceBits(mode<<rp.PWM_CH0_CSR_DIVMODE_Pos, rp.PWM_CH0_CSR_DIVMODE_Msk, 0) } // setPeriod sets the pwm peripheral period (frequency). Calculates DIV_INT,DIV_FRAC and sets it from following equation: -// cycles = (TOP+1) * (CSRPHCorrect + 1) * (DIV_INT + DIV_FRAC/16) +// +// cycles = (TOP+1) * (CSRPHCorrect + 1) * (DIV_INT + DIV_FRAC/16) +// // where cycles is amount of clock cycles per PWM period. func (pwm *pwmGroup) setPeriod(period uint64) error { // This period calculation algorithm consists of @@ -303,7 +308,7 @@ func (pwm *pwmGroup) setPeriod(period uint64) error { // frac's (DIV_FRAC) default value on reset is 0. Max value for frac is 15 (4 bits). This is known as a fixed-point // fractional number. // -// cycles = (TOP+1) * (CSRPHCorrect + 1) * (DIV_INT + DIV_FRAC/16) +// cycles = (TOP+1) * (CSRPHCorrect + 1) * (DIV_INT + DIV_FRAC/16) func (pwm *pwmGroup) setClockDiv(Int, frac uint8) { pwm.DIV.ReplaceBits((uint32(frac)<<rp.PWM_CH0_DIV_FRAC_Pos)| u32max(uint32(Int), 1)<<rp.PWM_CH0_DIV_INT_Pos, rp.PWM_CH0_DIV_FRAC_Msk|rp.PWM_CH0_DIV_INT_Msk, 0) |