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#include <global.h>
int main(void) {
RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
GPIOA->MODER |= (2 << GPIO_MODER_MODER9_Pos);
GPIOA->AFR[1] = (7 << (9-8)*4);
SystemCoreClockUpdate();
int apb2_clock = SystemCoreClock / APB2_PRESC;
int baudrate = 115200;
USART1->CR1 = USART_CR1_MME | USART_CR1_TE;
USART1->BRR = (apb2_clock + baudrate/2) / baudrate;
USART1->CR1 |= USART_CR1_UE;
char s[12] = {
'0', '0', '0', '0', '0',
' ', 'T', 'E', 'S', 'T',
'\n', '\0'};
int line = 0;
char *c = s;
USART1->TDR = *(c++); /* Kick off transmission */
while (23) {
if (USART1->ISR & USART_ISR_TXE) {
for (int i=0; i<100; i++)
asm volatile ("nop");
USART1->TDR = *(c++);
if (!*c) {
c = s;
line++;
int tmp = line;
tmp %= 100000;
s[0] = '0' + tmp/10000;
tmp %= 10000;
s[1] = '0' + tmp/1000;
tmp %= 1000;
s[2] = '0' + tmp/100;
tmp %= 100;
s[3] = '0' + tmp/10;
tmp %= 10;
s[4] = '0' + tmp;
}
}
}
}
void __libc_init_array (void) __attribute__((weak));
void __libc_init_array ()
{
}
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