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Fork of
mbed-dev-f303
by 
Ben Katz
Revision 123:5dbefb20d136, committed 2016-05-05
- Comitter:
- mbed_official
- Date:
- Thu May 05 21:00:11 2016 +0100
- Parent:
- 122:18a6c3abfbc7
- Child:
- 124:6a4a5b7d7324
- Commit message:
- Synchronized with git revision 53b54323ba1513a5aa427d241594a7c0d1ed8786
Full URL: https://github.com/mbedmicro/mbed/commit/53b54323ba1513a5aa427d241594a7c0d1ed8786/
Fix pwmout for STM32F3
Changed in this revision
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_DISCO_F303VC/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_DISCO_F303VC/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_DISCO_F334C8/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_DISCO_F334C8/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F302R8/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F302R8/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F303K8/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F303K8/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F303RE/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F303RE/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F334R8/objects.h Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/TARGET_NUCLEO_F334R8/objects.h Thu May 05 21:00:11 2016 +0100
@@ -99,6 +99,7 @@
struct pwmout_s {
PWMName pwm;
PinName pin;
+ uint32_t prescaler;
uint32_t period;
uint32_t pulse;
uint32_t channel;
--- a/targets/hal/TARGET_STM/TARGET_STM32F3/pwmout_api.c Wed May 04 22:30:12 2016 +0100
+++ b/targets/hal/TARGET_STM/TARGET_STM32F3/pwmout_api.c Thu May 05 21:00:11 2016 +0100
@@ -96,7 +96,7 @@
// Configure channels
sConfig.OCMode = TIM_OCMODE_PWM1;
- sConfig.Pulse = obj->pulse;
+ sConfig.Pulse = obj->pulse / obj->prescaler;
sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfig.OCNPolarity = TIM_OCNPOLARITY_HIGH;
sConfig.OCFastMode = TIM_OCFAST_DISABLE;
@@ -161,8 +161,26 @@
// Update the SystemCoreClock variable
SystemCoreClockUpdate();
- TimHandle.Init.Period = us - 1;
- TimHandle.Init.Prescaler = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 us tick
+ /* To make it simple, we use to possible prescaler values which lead to:
+ * pwm unit = 1us, period/pulse can be from 1us to 65535us
+ * or
+ * pwm unit = 500us, period/pulse can be from 500us to ~32.76sec
+ * Be careful that all the channels of a PWM shares the same prescaler
+ */
+ if (us > 0xFFFF) {
+ obj->prescaler = 500;
+ } else {
+ obj->prescaler = 1;
+ }
+ TimHandle.Init.Prescaler = ((SystemCoreClock / 1000000) * obj->prescaler) - 1;
+
+ if (TimHandle.Init.Prescaler > 0xFFFF)
+ error("PWM: out of range prescaler");
+
+ TimHandle.Init.Period = (us - 1) / obj->prescaler;
+ if (TimHandle.Init.Period > 0xFFFF)
+ error("PWM: out of range period");
+
TimHandle.Init.ClockDivision = 0;
TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;