tinyriscv/sdk/examples/uart_int/main.c

81 lines
2.0 KiB
C

#include <stdint.h>
#include "../../bsp/include/uart.h"
#include "../../bsp/include/xprintf.h"
#include "../../bsp/include/rvic.h"
#include "../../bsp/include/utils.h"
#include "../../bsp/include/pinmux.h"
#define UART_TXB (80)
static volatile struct {
uint16_t tri, twi, tct;
uint8_t tbuf[UART_TXB];
} fifo;
static void uart_putc(uint8_t c)
{
uint16_t i;
if (fifo.tct >= UART_TXB)
return;
i = fifo.twi;
fifo.tbuf[i] = c;
fifo.twi = ++i % UART_TXB;
global_irq_disable();
fifo.tct++;
// 使能TX FIFO空中断
UART0_REG(UART_CTRL_REG_OFFSET) |= 1 << UART_CTRL_TX_FIFO_EMPTY_INT_EN_BIT;
global_irq_enable();
}
int main()
{
pinmux_set_io0_func(IO0_UART0_TX);
pinmux_set_io3_func(IO3_UART0_RX);
uart0_init(uart_putc);
rvic_irq_enable(1);
rvic_set_irq_prio_level(1, 1);
// 使能RX FIFO非空中断
UART0_REG(UART_CTRL_REG_OFFSET) |= 1 << UART_CTRL_RX_FIFO_NOT_EMPTY_INT_EN_BIT;
global_irq_enable();
fifo.tri = 0; fifo.twi = 0; fifo.tct = 0;
xprintf("uart interrupt test\n");
while (1);
}
void uart0_irq_handler()
{
uint16_t i, count, index;
uint8_t data;
// 如果RX FIFO非空
while (!(UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_RXEMPTY_BIT))) {
data = UART0_REG(UART_RXDATA_REG_OFFSET);
UART0_REG(UART_TXDATA_REG_OFFSET) = data;
}
// 如果TX FIFO为空
if ((UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_TXEMPTY_BIT)) &&
(fifo.tct > 0)) {
count = fifo.tct;
if (count > 8)
count = 8;
for (index = 0; index < count; index++) {
fifo.tct--;
i = fifo.tri;
UART0_REG(UART_TXDATA_REG_OFFSET) = fifo.tbuf[i];
fifo.tri = ++i % UART_TXB;
}
if (fifo.tct == 0)
UART0_REG(UART_CTRL_REG_OFFSET) &= ~(1 << UART_CTRL_TX_FIFO_EMPTY_INT_EN_BIT);
}
rvic_clear_irq_pending(1);
}