Yaroslav Barabanov / Stm32F1xx_Alternative

Here, alternative functions and classes for STM32. The program contains a class for the I2C software bus, a class for working with a watchdog timer and time delay functions based on DWT. All functions and classes use the HAL library. Functions and classes were written for the microcontroller stm32f103.

Dependents:   STM32_F1XX_Alternative

AlternativeDelay.cpp@1:0d39ea4dee8b, 2017-05-24 (annotated)

Committer:
Yar
Date:
Wed May 24 20:35:23 2017 +0000
Revision:
1:0d39ea4dee8b
Parent:
0:2f819bf6cd99 
Fixed a bug with a delay of milliseconds

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yar 0:2f819bf6cd99 1 #include "AlternativeDelay.hpp"
Yar 0:2f819bf6cd99 2 #include "stm32f1xx_hal.h"
Yar 0:2f819bf6cd99 3 #include "mbed.h"
Yar 0:2f819bf6cd99 4
Yar 0:2f819bf6cd99 5 #define DWT_CYCCNT *(volatile unsigned long *)0xE0001004
Yar 0:2f819bf6cd99 6 #define DWT_CONTROL *(volatile unsigned long *)0xE0001000
Yar 0:2f819bf6cd99 7 #define SCB_DEMCR *(volatile unsigned long *)0xE000EDFC
Yar 0:2f819bf6cd99 8
Yar 1:0d39ea4dee8b 9 void initializeTimeDelays(void) {
Yar 0:2f819bf6cd99 10 // allow to use the counter
Yar 0:2f819bf6cd99 11 SCB_DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
Yar 0:2f819bf6cd99 12 // zero the value of the register register
Yar 0:2f819bf6cd99 13 DWT_CYCCNT = 0;
Yar 0:2f819bf6cd99 14 // start the counter
Yar 0:2f819bf6cd99 15 DWT_CONTROL |= DWT_CTRL_CYCCNTENA_Msk;
Yar 0:2f819bf6cd99 16 }
Yar 0:2f819bf6cd99 17
Yar 0:2f819bf6cd99 18 static __inline uint32_t delta(uint32_t t0, uint32_t t1) {
Yar 0:2f819bf6cd99 19 return (t1 - t0);
Yar 0:2f819bf6cd99 20 }
Yar 0:2f819bf6cd99 21
Yar 0:2f819bf6cd99 22 void delay_us(uint32_t us) {
Yar 1:0d39ea4dee8b 23 if (!(SCB_DEMCR & CoreDebug_DEMCR_TRCENA_Msk)) {
Yar 1:0d39ea4dee8b 24 // allow to use the counter
Yar 1:0d39ea4dee8b 25 SCB_DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
Yar 1:0d39ea4dee8b 26 // zero the value of the register register
Yar 1:0d39ea4dee8b 27 DWT_CYCCNT = 0;
Yar 1:0d39ea4dee8b 28 // start the counter
Yar 1:0d39ea4dee8b 29 DWT_CONTROL |= DWT_CTRL_CYCCNTENA_Msk;
Yar 1:0d39ea4dee8b 30 //isInitializationDWT = true;
Yar 1:0d39ea4dee8b 31 }
Yar 0:2f819bf6cd99 32 uint32_t t0 = DWT->CYCCNT;
Yar 0:2f819bf6cd99 33 uint32_t us_count_tic = us * (SystemCoreClock/1000000);
Yar 0:2f819bf6cd99 34 while (delta(t0, DWT->CYCCNT) < us_count_tic) ;
Yar 0:2f819bf6cd99 35 }
Yar 0:2f819bf6cd99 36
Yar 0:2f819bf6cd99 37 void delay_ms(uint32_t ms) {
Yar 1:0d39ea4dee8b 38 if (!(SCB_DEMCR & CoreDebug_DEMCR_TRCENA_Msk)) {
Yar 1:0d39ea4dee8b 39 // allow to use the counter
Yar 1:0d39ea4dee8b 40 SCB_DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
Yar 1:0d39ea4dee8b 41 // zero the value of the register register
Yar 1:0d39ea4dee8b 42 DWT_CYCCNT = 0;
Yar 1:0d39ea4dee8b 43 // start the counter
Yar 1:0d39ea4dee8b 44 DWT_CONTROL |= DWT_CTRL_CYCCNTENA_Msk;
Yar 1:0d39ea4dee8b 45 //isInitializationDWT = true;
Yar 0:2f819bf6cd99 46 }
Yar 0:2f819bf6cd99 47 uint32_t t0 = DWT->CYCCNT;
Yar 1:0d39ea4dee8b 48 uint32_t us_count_tic = ms * (SystemCoreClock/1000);
Yar 0:2f819bf6cd99 49 while (delta(t0, DWT->CYCCNT) < us_count_tic) ;
Yar 1:0d39ea4dee8b 50 }
Yar 1:0d39ea4dee8b 51