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Fix to allow STM32 PWM frequencies to go below 1100 Hz

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This commit is contained in:
James Snyder 2011-03-14 16:17:58 -05:00
parent 957dab161d
commit 3e1248ebc6
1 changed files with 15 additions and 9 deletions
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24
src/platform/stm32/platform.c
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@ -857,16 +857,22 @@ static u32 platform_pwm_set_clock( u32 clock )
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TypeDef* ptimer = PWM_TIMER_NAME;
unsigned period, prescaler;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = ( TIM_GET_BASE_CLK( PWM_TIMER_ID ) / clock ) - 1;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
period = TIM_GET_BASE_CLK( PWM_TIMER_ID ) / clock;
prescaler = (period / 0x10000) + 1;
period /= prescaler;
TIM_TimeBaseStructure.TIM_Period = period - 1;
TIM_TimeBaseStructure.TIM_Prescaler = prescaler - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0000;
TIM_TimeBaseInit( ptimer, &TIM_TimeBaseStructure );
return ( TIM_GET_BASE_CLK( PWM_TIMER_ID ) / ( TIM_TimeBaseStructure.TIM_Period + 1 ) ) ;
return platform_pwm_get_clock();
}
u32 platform_pwm_setup( unsigned id, u32 frequency, unsigned duty )
@ -1164,13 +1170,13 @@ u32 platform_adc_setclock( unsigned id, u32 frequency )
period = TIM_GET_BASE_CLK( id ) / frequency;
prescaler = (period / 0x10000) + 1;
period /= prescaler;
period /= prescaler;
timer_base_struct.TIM_Period = period - 1;
timer_base_struct.TIM_Prescaler = prescaler - 1;
timer_base_struct.TIM_ClockDivision = TIM_CKD_DIV1;
timer_base_struct.TIM_CounterMode = TIM_CounterMode_Down;
TIM_TimeBaseInit( timer[ d->timer_id ], &timer_base_struct );
timer_base_struct.TIM_Period = period - 1;
timer_base_struct.TIM_Prescaler = prescaler - 1;
timer_base_struct.TIM_ClockDivision = TIM_CKD_DIV1;
timer_base_struct.TIM_CounterMode = TIM_CounterMode_Down;
TIM_TimeBaseInit( timer[ d->timer_id ], &timer_base_struct );
frequency = ( TIM_GET_BASE_CLK( id ) / ( TIM_GetPrescaler( timer[ d->timer_id ] ) + 1 ) ) / period;