cc2538定时器记脉冲数

看你是否需要timer继续运行
When counting down in Input Edge-Count Mode, the timer stops after the programmed number of edge events has been detected. To re-enable the timer, ensure that the TnEN bit is cleared and repeat #4 through #9.
In Input Edge Timing mode, the timer continues running after an edge event has been detected, but the timer interval can be changed at any time by writing the GPTMTnILR register. The change takes effect at the next cycle after the write.

你好，我想用定时器计PC6接的按键按了几次，结果串口啥都没打印出来，下面是我的代码，能帮我看看哪些地方不对吗，谢谢
#include "contiki.h"
#include "dev/gptimer.h"
#include "dev/ioc.h"
#include "dev/sys-ctrl.h"
#include "dev/uart.h"
#include "reg.h"
#include <stdio.h>


void timer0_init(uint16_t psc, uint16_t arr)
{
/*Clock for GPT0 is enabled*/
REG(SYS_CTRL_RCGCGPT) = 1;

REG(IOC_PC4_SEL) = 0xD;

/*Timer A is disabled. Positive edge. Negative edge*/
REG(GPT_0_BASE + GPTIMER_CTL) = 0x4;

/*16-bit timer configuration*/
REG(GPT_0_BASE + GPTIMER_CFG) = 0x4;

/*The timer counts up. When counting up, the timer starts from a
value of 0x0.Edge-time mode.Capture mode*/
REF(GPT_0_BASE + GPTIMER_TAMR) = 0x10 | 0x4 | GPTIMER_TAMR_TAMR_CAPTURE;

/*GPTM Timer A prescale*/
REG(GPT_0_BASE + GPTIMER_TAPR) = psc;

/*GPTM A interval load register*/
REG(GPT_0_BASE + GPTIMER_TAILR) = arr;

/* Timer A is enabled and begins counting or the capture logic is
enabled based on the GPTMCFG register.*/
REG(GPT_0_BASE + GPTIMER_CTL) |= 1;

}

PROCESS(timer0_process, "spi");
AUTOSTART_PROCESSES(&timer0_process);
PROCESS_THREAD(timer0_process, ev, data)
{
uint16_t count;
PROCESS_BEGIN();
uart_init();
timer0_init(0, 0xFFFF);
while(1)
{

if (count != REG(GPT_0_BASE + GPTIMER_TAR))
{
count = REG(GPT_0_BASE + GPTIMER_TAR);
printf("cnt: %d\n", count);
}
}
PROCESS_END();
}