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authorDave Hylands <dhylands@gmail.com>2014-10-10 09:56:41 -0700
committerDave Hylands <dhylands@gmail.com>2014-10-10 13:54:03 -0700
commit1c795445b31a73bcff71eac4ce56827554b4f29f (patch)
tree3253e564053556bb7a472e537b93b3d64172fa68 /stmhal/timer.c
parent9b6617ea8b2324993e709058dd1a74433a9001a6 (diff)
downloadmicropython-1c795445b31a73bcff71eac4ce56827554b4f29f.tar.gz
micropython-1c795445b31a73bcff71eac4ce56827554b4f29f.zip
Add support for complimentary channel output and deadtime.
This patch enables output on the complimentary channels (TIMx_CHyN). For timers 1 and 8, deadtime can also be inserted when the channels transition. For the pyboard, TIM8_CH1/CH1N and TIM8_CH2/CH2N can take advantage of this.
Diffstat (limited to 'stmhal/timer.c')
-rw-r--r--stmhal/timer.c88
1 files changed, 86 insertions, 2 deletions
diff --git a/stmhal/timer.c b/stmhal/timer.c
index 787a6dd981..5c99d51f19 100644
--- a/stmhal/timer.c
+++ b/stmhal/timer.c
@@ -414,6 +414,59 @@ STATIC mp_obj_t compute_percent_from_pwm_value(uint32_t period, uint32_t cmp) {
#endif
}
+// Computes the 8-bit value for the DTG field in the BDTR register.
+//
+// 1 tick = 1 count of the timer's clock (source_freq) divided by div.
+// 0-128 ticks in inrements of 1
+// 128-256 ticks in increments of 2
+// 256-512 ticks in increments of 8
+// 512-1008 ticks in increments of 16
+STATIC uint32_t compute_dtg_from_ticks(mp_int_t ticks) {
+ if (ticks <= 0) {
+ return 0;
+ }
+ if (ticks < 128) {
+ return ticks;
+ }
+ if (ticks < 256) {
+ return 0x80 | ((ticks - 128) / 2);
+ }
+ if (ticks < 512) {
+ return 0xC0 | ((ticks - 256) / 8);
+ }
+ if (ticks < 1008) {
+ return 0xE0 | ((ticks - 512) / 16);
+ }
+ return 0xFF;
+}
+
+// Given the 8-bit value stored in the DTG field of the BDTR register, compute
+// the number of ticks.
+STATIC mp_int_t compute_ticks_from_dtg(uint32_t dtg) {
+ if ((dtg & 0x80) == 0) {
+ return dtg & 0x7F;
+ }
+ if ((dtg & 0xC0) == 0x80) {
+ return 128 + ((dtg & 0x3F) * 2);
+ }
+ if ((dtg & 0xE0) == 0xC0) {
+ return 256 + ((dtg & 0x1F) * 8);
+ }
+ return 512 + ((dtg & 0x1F) * 16);
+}
+
+STATIC void config_deadtime(pyb_timer_obj_t *self, mp_int_t ticks) {
+ TIM_BreakDeadTimeConfigTypeDef deadTimeConfig;
+ deadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
+ deadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
+ deadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
+ deadTimeConfig.DeadTime = compute_dtg_from_ticks(ticks);
+ deadTimeConfig.BreakState = TIM_BREAK_DISABLE;
+ deadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_LOW;
+ deadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
+ HAL_TIMEx_ConfigBreakDeadTime(&self->tim, &deadTimeConfig);
+}
+
STATIC void pyb_timer_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_timer_obj_t *self = self_in;
@@ -424,7 +477,7 @@ STATIC void pyb_timer_print(void (*print)(void *env, const char *fmt, ...), void
uint32_t period = __HAL_TIM_GetAutoreload(&self->tim) & TIMER_CNT_MASK(self);
// for efficiency, we compute and print freq as an int (not a float)
uint32_t freq = timer_get_source_freq(self->tim_id) / ((prescaler + 1) * (period + 1));
- print(env, "Timer(%u, freq=%u, prescaler=%u, period=%u, mode=%s, div=%u)",
+ print(env, "Timer(%u, freq=%u, prescaler=%u, period=%u, mode=%s, div=%u",
self->tim_id,
freq,
prescaler,
@@ -433,6 +486,10 @@ STATIC void pyb_timer_print(void (*print)(void *env, const char *fmt, ...), void
self->tim.Init.CounterMode == TIM_COUNTERMODE_DOWN ? "DOWN" : "CENTER",
self->tim.Init.ClockDivision == TIM_CLOCKDIVISION_DIV4 ? 4 :
self->tim.Init.ClockDivision == TIM_CLOCKDIVISION_DIV2 ? 2 : 1);
+ if (IS_TIM_ADVANCED_INSTANCE(self->tim.Instance)) {
+ print(env, ", deadtime=%u", compute_ticks_from_dtg(self->tim.Instance->BDTR & TIM_BDTR_DTG));
+ }
+ print(env, ")");
}
}
@@ -472,6 +529,14 @@ STATIC void pyb_timer_print(void (*print)(void *env, const char *fmt, ...), void
///
/// - `callback` - as per Timer.callback()
///
+/// - `deadtime` - specifies the amount of "dead" or inactive time between
+/// transitions on complimentary channels (both channels will be inactive)
+/// for this time). `deadtime` may be an integer between 0 and 1008, with
+/// the following restrictions: 0-128 in steps of 1. 128-256 in steps of
+/// 2, 256-512 in steps of 8, and 512-1008 in steps of 16. `deadime`
+/// measures ticks of `source_freq` divided by `div` clock ticks.
+/// `deadtime` is only available on timers 1 and 8.
+///
/// You must either specify freq or both of period and prescaler.
STATIC mp_obj_t pyb_timer_init_helper(pyb_timer_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
@@ -481,6 +546,7 @@ STATIC mp_obj_t pyb_timer_init_helper(pyb_timer_obj_t *self, mp_uint_t n_args, c
{ MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = TIM_COUNTERMODE_UP} },
{ MP_QSTR_div, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_callback, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+ { MP_QSTR_deadtime, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
// parse args
@@ -537,6 +603,9 @@ STATIC mp_obj_t pyb_timer_init_helper(pyb_timer_obj_t *self, mp_uint_t n_args, c
// init TIM
HAL_TIM_Base_Init(&self->tim);
+ if (IS_TIM_ADVANCED_INSTANCE(self->tim.Instance)) {
+ config_deadtime(self, args[6].u_int);
+ }
if (args[5].u_obj == mp_const_none) {
HAL_TIM_Base_Start(&self->tim);
} else {
@@ -685,6 +754,9 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_deinit_obj, pyb_timer_deinit);
/// - `Timer.FALLING` - captures on falling edge.
/// - `Timer.BOTH` - captures on both edges.
///
+/// Note that capture only works on the primary channel, and not on the
+/// complimentary channels.
+///
/// PWM Example:
///
/// timer = pyb.Timer(2, freq=1000)
@@ -808,6 +880,10 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
} else {
HAL_TIM_PWM_Start_IT(&self->tim, TIMER_CHANNEL(chan));
}
+ // Start the complimentary channel too (if its supported)
+ if (IS_TIM_CCXN_INSTANCE(self->tim.Instance, TIMER_CHANNEL(chan))) {
+ HAL_TIMEx_PWMN_Start(&self->tim, TIMER_CHANNEL(chan));
+ }
break;
}
@@ -824,7 +900,11 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
if (oc_config.OCPolarity == 0xffffffff) {
oc_config.OCPolarity = TIM_OCPOLARITY_HIGH;
}
- oc_config.OCNPolarity = TIM_OCNPOLARITY_HIGH;
+ if (oc_config.OCPolarity == TIM_OCPOLARITY_HIGH) {
+ oc_config.OCNPolarity = TIM_OCNPOLARITY_HIGH;
+ } else {
+ oc_config.OCNPolarity = TIM_OCNPOLARITY_LOW;
+ }
oc_config.OCFastMode = TIM_OCFAST_DISABLE;
oc_config.OCIdleState = TIM_OCIDLESTATE_SET;
oc_config.OCNIdleState = TIM_OCNIDLESTATE_SET;
@@ -838,6 +918,10 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
} else {
HAL_TIM_OC_Start_IT(&self->tim, TIMER_CHANNEL(chan));
}
+ // Start the complimentary channel too (if its supported)
+ if (IS_TIM_CCXN_INSTANCE(self->tim.Instance, TIMER_CHANNEL(chan))) {
+ HAL_TIMEx_OCN_Start(&self->tim, TIMER_CHANNEL(chan));
+ }
break;
}
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