ao_sleep(&ao_forever);
}
-#define T2_CLOCK_DIVISOR 8 /* 24e6/8 = 3e6 */
-#define T2_SAMPLE_TIME 30000 /* 3e6/30000 = 100 */
-
#if HAS_ADC
volatile __data uint8_t ao_adc_interval = 1;
volatile __data uint8_t ao_adc_count;
ao_debug_out(char c);
-void tim2_isr(void)
+void stm_tim6_isr(void)
{
- ++ao_tick_count;
+ if (stm_tim6.sr & (1 << STM_TIM67_SR_UIF)) {
+ stm_tim6.sr = 0;
+ ++ao_tick_count;
#if HAS_ADC
- if (++ao_adc_count == ao_adc_interval) {
- ao_adc_count = 0;
- ao_adc_poll();
- }
+ if (++ao_adc_count == ao_adc_interval) {
+ ao_adc_count = 0;
+ ao_adc_poll();
+ }
#endif
+ }
}
#if HAS_ADC
}
#endif
+/*
+ * According to the STM clock-configuration, timers run
+ * twice as fast as the APB1 clock *if* the APB1 prescaler
+ * is greater than 1.
+ */
+
+#if AO_APB1_PRESCALER > 1
+#define TIMER_23467_SCALER 2
+#else
+#define TIMER_23467_SCALER 1
+#endif
+
+#define TIMER_10kHz ((AO_PCLK1 * TIMER_23467_SCALER) / 10000)
+
void
ao_timer_init(void)
{
+ stm_nvic_set_enable(STM_ISR_TIM6_POS);
+ stm_nvic_set_priority(STM_ISR_TIM6_POS, 1);
+
+ /* Turn on timer 6 */
+ stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_TIM6EN);
+
+ stm_tim6.psc = TIMER_10kHz;
+ stm_tim6.arr = 100;
+ stm_tim6.cnt = 0;
+
+ /* Enable update interrupt */
+ stm_tim6.dier = (1 << STM_TIM67_DIER_UIE);
+
+ /* Poke timer to reload values */
+ stm_tim6.egr |= (1 << STM_TIM67_EGR_UG);
+
+ stm_tim6.cr2 = (STM_TIM67_CR2_MMS_RESET << STM_TIM67_CR2_MMS);
+
+ /* And turn it on */
+ stm_tim6.cr1 = ((0 << STM_TIM67_CR1_ARPE) |
+ (0 << STM_TIM67_CR1_OPM) |
+ (1 << STM_TIM67_CR1_URS) |
+ (0 << STM_TIM67_CR1_UDIS) |
+ (1 << STM_TIM67_CR1_CEN));
}
void
ao_clock_init(void)
{
uint32_t cfgr;
+ uint32_t cr;
+ /* Switch to MSI while messing about */
+ stm_rcc.cr |= (1 << STM_RCC_CR_MSION);
+ while (!(stm_rcc.cr & (1 << STM_RCC_CR_MSIRDY)))
+ asm("nop");
+
+ /* reset SW, HPRE, PPRE1, PPRE2, MCOSEL and MCOPRE */
+ stm_rcc.cfgr &= (uint32_t)0x88FFC00C;
+
+ /* reset HSION, HSEON, CSSON and PLLON bits */
+ stm_rcc.cr &= 0xeefefffe;
+
+ /* reset PLLSRC, PLLMUL and PLLDIV bits */
+ stm_rcc.cfgr &= 0xff02ffff;
+
+ /* Disable all interrupts */
+ stm_rcc.cir = 0;
+
+#if AO_HSE
+#if AO_HSE_BYPASS
+ stm_rcc.cr |= (1 << STM_RCC_CR_HSEBYP);
+#else
+ stm_rcc.cr &= ~(1 << STM_RCC_CR_HSEBYP);
+#endif
+ /* Enable HSE clock */
+ stm_rcc.cr |= (1 << STM_RCC_CR_HSEON);
+ while (!(stm_rcc.cr & (1 << STM_RCC_CR_HSERDY)))
+ asm("nop");
+
+#define STM_RCC_CFGR_SWS_TARGET_CLOCK (STM_RCC_CFGR_SWS_HSE << STM_RCC_CFGR_SWS)
+#define STM_RCC_CFGR_SW_TARGET_CLOCK (STM_RCC_CFGR_SW_HSE)
+#define STM_PLLSRC AO_HSE
+#define STM_RCC_CFGR_PLLSRC_TARGET_CLOCK (1 << STM_RCC_CFGR_PLLSRC)
+#else
+#define STM_HSI 16000000
+#define STM_RCC_CFGR_SWS_TARGET_CLOCK (STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS)
+#define STM_RCC_CFGR_SW_TARGET_CLOCK (STM_RCC_CFGR_SW_HSI)
+#define STM_PLLSRC STM_HSI
+#define STM_RCC_CFGR_PLLSRC_TARGET_CLOCK (0 << STM_RCC_CFGR_PLLSRC)
+#endif
+
+#if !AO_HSE || HAS_ADC
+ /* Enable HSI RC clock 16MHz */
+ stm_rcc.cr |= (1 << STM_RCC_CR_HSION);
+ while (!(stm_rcc.cr & (1 << STM_RCC_CR_HSIRDY)))
+ asm("nop");
+#endif
+
/* Set flash latency to tolerate 32MHz SYSCLK -> 1 wait state */
- uint32_t acr = STM_FLASH->acr;
/* Enable 64-bit access and prefetch */
- acr |= (1 << STM_FLASH_ACR_ACC64) | (1 << STM_FLASH_ACR_PRFEN);
- STM_FLASH->acr = acr;
+ stm_flash.acr |= (1 << STM_FLASH_ACR_ACC64);
+ stm_flash.acr |= (1 << STM_FLASH_ACR_PRFEN);
/* Enable 1 wait state so the CPU can run at 32MHz */
- acr |= (1 << STM_FLASH_ACR_LATENCY);
- STM_FLASH->acr = acr;
+ /* (haven't managed to run the CPU at 32MHz yet, it's at 16MHz) */
+ stm_flash.acr |= (1 << STM_FLASH_ACR_LATENCY);
- /* Enable HSI RC clock 16MHz */
- if (!(STM_RCC->cr & (1 << STM_RCC_CR_HSIRDY))) {
- STM_RCC->cr |= (1 << STM_RCC_CR_HSION);
- while (!(STM_RCC->cr & (1 << STM_RCC_CR_HSIRDY)))
- asm("nop");
- }
+ /* Enable power interface clock */
+ stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
- /* Switch to direct HSI for SYSCLK */
- if ((STM_RCC->cfgr & (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS)) !=
- (STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS)) {
- cfgr = STM_RCC->cfgr;
- cfgr &= ~(STM_RCC_CFGR_SW_MASK << STM_RCC_CFGR_SW);
- cfgr |= (STM_RCC_CFGR_SW_HSI << STM_RCC_CFGR_SW);
- STM_RCC->cfgr = cfgr;
- while ((STM_RCC->cfgr & (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS)) !=
- (STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS))
- asm("nop");
- }
+ /* Set voltage range to 1.8V */
+
+ /* poll VOSF bit in PWR_CSR. Wait until it is reset to 0 */
+ while ((stm_pwr.csr & (1 << STM_PWR_CSR_VOSF)) != 0)
+ asm("nop");
+
+ /* Configure voltage scaling range */
+ cr = stm_pwr.cr;
+ cr &= ~(STM_PWR_CR_VOS_MASK << STM_PWR_CR_VOS);
+ cr |= (STM_PWR_CR_VOS_1_8 << STM_PWR_CR_VOS);
+ stm_pwr.cr = cr;
+
+ /* poll VOSF bit in PWR_CSR. Wait until it is reset to 0 */
+ while ((stm_pwr.csr & (1 << STM_PWR_CSR_VOSF)) != 0)
+ asm("nop");
+
+ /* HCLK to 16MHz -> AHB prescaler = /1 */
+ cfgr = stm_rcc.cfgr;
+ cfgr &= ~(STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE);
+ cfgr |= (AO_RCC_CFGR_HPRE_DIV << STM_RCC_CFGR_HPRE);
+ stm_rcc.cfgr = cfgr;
+ while ((stm_rcc.cfgr & (STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE)) !=
+ (AO_RCC_CFGR_HPRE_DIV << STM_RCC_CFGR_HPRE))
+ asm ("nop");
+
+ /* APB1 Prescaler = AO_APB1_PRESCALER */
+ cfgr = stm_rcc.cfgr;
+ cfgr &= ~(STM_RCC_CFGR_PPRE1_MASK << STM_RCC_CFGR_PPRE1);
+ cfgr |= (AO_RCC_CFGR_PPRE1_DIV << STM_RCC_CFGR_PPRE1);
+ stm_rcc.cfgr = cfgr;
+
+ /* APB2 Prescaler = AO_APB2_PRESCALER */
+ cfgr = stm_rcc.cfgr;
+ cfgr &= ~(STM_RCC_CFGR_PPRE2_MASK << STM_RCC_CFGR_PPRE2);
+ cfgr |= (AO_RCC_CFGR_PPRE2_DIV << STM_RCC_CFGR_PPRE2);
+ stm_rcc.cfgr = cfgr;
/* Disable the PLL */
- STM_RCC->cr &= ~(1 << STM_RCC_CR_PLLON);
- while (STM_RCC->cr & (1 << STM_RCC_CR_PLLRDY))
+ stm_rcc.cr &= ~(1 << STM_RCC_CR_PLLON);
+ while (stm_rcc.cr & (1 << STM_RCC_CR_PLLRDY))
asm("nop");
- /* PLLVCO to 96MHz (for USB) -> PLLMUL = 6 */
- cfgr = STM_RCC->cfgr;
+ /* PLLVCO to 96MHz (for USB) -> PLLMUL = 6, PLLDIV = 4 */
+ cfgr = stm_rcc.cfgr;
cfgr &= ~(STM_RCC_CFGR_PLLMUL_MASK << STM_RCC_CFGR_PLLMUL);
- cfgr |= (STM_RCC_CFGR_PLLMUL_6 << STM_RCC_CFGR_PLLMUL);
-
- /* SYSCLK to 32MHz from PLL clock -> PLLDIV = /3 */
cfgr &= ~(STM_RCC_CFGR_PLLDIV_MASK << STM_RCC_CFGR_PLLDIV);
- cfgr |= (STM_RCC_CFGR_PLLDIV_3 << STM_RCC_CFGR_PLLDIV);
- /* PLL source to HSI */
+ cfgr |= (AO_RCC_CFGR_PLLMUL << STM_RCC_CFGR_PLLMUL);
+ cfgr |= (AO_RCC_CFGR_PLLDIV << STM_RCC_CFGR_PLLDIV);
+
+ /* PLL source */
cfgr &= ~(1 << STM_RCC_CFGR_PLLSRC);
+ cfgr |= STM_RCC_CFGR_PLLSRC_TARGET_CLOCK;
- STM_RCC->cfgr = cfgr;
+ stm_rcc.cfgr = cfgr;
/* Enable the PLL and wait for it */
- STM_RCC->cr |= (1 << STM_RCC_CR_PLLON);
- while (!(STM_RCC->cr & (1 << STM_RCC_CR_PLLRDY)))
+ stm_rcc.cr |= (1 << STM_RCC_CR_PLLON);
+ while (!(stm_rcc.cr & (1 << STM_RCC_CR_PLLRDY)))
asm("nop");
/* Switch to the PLL for the system clock */
- cfgr = STM_RCC->cfgr;
+ cfgr = stm_rcc.cfgr;
cfgr &= ~(STM_RCC_CFGR_SW_MASK << STM_RCC_CFGR_SW);
cfgr |= (STM_RCC_CFGR_SW_PLL << STM_RCC_CFGR_SW);
- STM_RCC->cfgr = cfgr;
- while ((STM_RCC->cfgr & (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS)) !=
- (STM_RCC_CFGR_SWS_PLL << STM_RCC_CFGR_SWS))
- asm("nop");
+ stm_rcc.cfgr = cfgr;
+ for (;;) {
+ uint32_t c, part, mask, val;
- /* HCLK to 32MHz -> AHB prescaler = /1 */
- cfgr = STM_RCC->cfgr;
- cfgr &= ~(STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE);
- cfgr |= (STM_RCC_CFGR_HPRE_DIV_1 << STM_RCC_CFGR_HPRE);
- STM_RCC->cfgr = cfgr;
- while ((STM_RCC->cfgr & (STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE)) !=
- (STM_RCC_CFGR_HPRE_DIV_1 << STM_RCC_CFGR_HPRE))
- asm ("nop");
+ c = stm_rcc.cfgr;
+ mask = (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS);
+ val = (STM_RCC_CFGR_SWS_PLL << STM_RCC_CFGR_SWS);
+ part = c & mask;
+ if (part == val)
+ break;
+ }
- /* PCLK1 to 16MHz -> APB1 Prescaler = 2 */
- cfgr = STM_RCC->cfgr;
- cfgr &= ~(STM_RCC_CFGR_PPRE1_MASK << STM_RCC_CFGR_PPRE1);
- cfgr |= (STM_RCC_CFGR_PPRE1_DIV_2 << STM_RCC_CFGR_PPRE1);
- STM_RCC->cfgr = cfgr;
+#if 0
+ stm_rcc.apb2rstr = 0xffff;
+ stm_rcc.apb1rstr = 0xffff;
+ stm_rcc.ahbrstr = 0x3f;
+ stm_rcc.ahbenr = (1 << STM_RCC_AHBENR_FLITFEN);
+ stm_rcc.apb2enr = 0;
+ stm_rcc.apb1enr = 0;
+ stm_rcc.ahbrstr = 0;
+ stm_rcc.apb1rstr = 0;
+ stm_rcc.apb2rstr = 0;
+#endif
- /* PCLK2 to 16MHz -> APB2 Prescaler = 2 */
- cfgr = STM_RCC->cfgr;
- cfgr &= ~(STM_RCC_CFGR_PPRE2_MASK << STM_RCC_CFGR_PPRE2);
- cfgr |= (STM_RCC_CFGR_PPRE2_DIV_2 << STM_RCC_CFGR_PPRE2);
- STM_RCC->cfgr = cfgr;
+ /* Clear reset flags */
+ stm_rcc.csr |= (1 << STM_RCC_CSR_RMVF);
+
+
+ /* Output SYSCLK on PA8 for measurments */
+
+ stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
+
+ stm_afr_set(&stm_gpioa, 8, STM_AFR_AF0);
+ stm_moder_set(&stm_gpioa, 8, STM_MODER_ALTERNATE);
+ stm_ospeedr_set(&stm_gpioa, 8, STM_OSPEEDR_40MHz);
+ stm_rcc.cfgr |= (STM_RCC_CFGR_MCOPRE_DIV_1 << STM_RCC_CFGR_MCOPRE);
+ stm_rcc.cfgr |= (STM_RCC_CFGR_MCOSEL_HSE << STM_RCC_CFGR_MCOSEL);
}