EMTime/libopencm3
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Use __asm__("nop") in the loop-based delays.

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Since we recently switched from -O0 to -Os, an increase in the loop count
as well as the addition of __asm__("nop") is required (so that the loop
doesn't get optimized/removed).
The real fix is to add a proper timer-based delay function, of course.

Also, fix a bunch of cosmetic issues and typos.
This commit is contained in:
Uwe Hermann
2011-01-03 01:12:07 +01:00
parent 05f66cde4c
commit ca53311bfc
11 changed files with 82 additions and 61 deletions
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13
examples/stm32/obldc/usart/usart.c
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@@ -25,7 +25,7 @@ void clock_setup(void)
{
rcc_clock_setup_in_hse_8mhz_out_72mhz();
/* Enable GPIOA clock. For LED gpio's */
/* Enable GPIOA clock (for LED GPIOs). */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
/* Enable clocks for GPIO port B (for GPIO_USART1_TX) and USART1. */
@@ -36,11 +36,9 @@ void clock_setup(void)
void usart_setup(void)
{
/* Setup GPIO6 (in GPIO port A) to 'output push-pull' for led use. */
/* Setup GPIO6 (in GPIO port A) to 'output push-pull' for LED use. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL,
GPIO6);
GPIO_CNF_OUTPUT_PUSHPULL, GPIO6);
AFIO_MAPR |= AFIO_MAPR_USART1_REMAP;
@@ -78,13 +76,14 @@ int main(void)
/* Blink the LED (PC12) on the board with every transmitted byte. */
while (1) {
gpio_toggle(GPIOA, GPIO6); /* LED on/off */
usart_send_blocking(USART1, c + '0'); /* Send one byte on USART3. */
usart_send_blocking(USART1, c + '0'); /* Send a byte. */
c = (c == 9) ? 0 : c + 1; /* Increment c. */
if ((j++ % 80) == 0) { /* Newline after line full. */
usart_send_blocking(USART1, '\r');
usart_send_blocking(USART1, '\n');
}
for (i = 0; i < 80000; i++); /* Wait (needs -O0 CFLAGS). */
for (i = 0; i < 800000; i++) /* Wait a bit. */
__asm__("nop");
}
return 0;