在线时间28 小时
UID1826152
注册时间2015-4-29
NXP金币0
该用户从未签到
注册会员

- 积分
- 144
- 最后登录
- 2019-7-1
|

楼主 |
发表于 2015-6-18 14:37:36
|
显示全部楼层
看例程HelloWorld用LPTMR初始化一定时器:
// LPTMR configurations
lptmr_user_config_t lptmrConfig =
{
.timerMode = kLptmrTimerModeTimeCounter,
.freeRunningEnable = false,
.prescalerEnable = true,
.prescalerClockSource = kClockLptmrSrcLpoClk,
.prescalerValue = kLptmrPrescalerDivide2,
.isInterruptEnabled = true,
};
lptmr_state_t lptmrState; // LPTMR driver state information
LPTMR_DRV_Init(LPTMR0_IDX, &lptmrState, &lptmrConfig); // Initialize LPTMR
LPTMR_DRV_SetTimerPeriodUs(LPTMR0_IDX, TMR_PERIOD); // Set timer period for TMR_PERIOD seconds
LPTMR_DRV_InstallCallback(LPTMR0_IDX, lptmr_call_back); // Install interrupt call back function for
LPTMR
LPTMR_DRV_Start(LPTMR0_IDX); // Start LPTMR
将这段代码放在main()中可以正确初始化LPTMR,可在中断中闪烁一LED。
但将这段代码放在一函数中,如:
void lptmr_func(void)
{
// LPTMR configurations
lptmr_user_config_t lptmrConfig =
{
.timerMode = kLptmrTimerModeTimeCounter,
.freeRunningEnable = false,
.prescalerEnable = true,
.prescalerClockSource = kClockLptmrSrcLpoClk,
.prescalerValue = kLptmrPrescalerDivide2,
.isInterruptEnabled = true,
};
lptmr_state_t lptmrState; // LPTMR driver state information
LPTMR_DRV_Init(LPTMR0_IDX, &lptmrState, &lptmrConfig); // Initialize LPTMR
LPTMR_DRV_SetTimerPeriodUs(LPTMR0_IDX, TMR_PERIOD); // Set timer period for TMR_PERIOD seconds
LPTMR_DRV_InstallCallback(LPTMR0_IDX, lptmr_call_back); // Install interrupt call back function for
LPTMR
LPTMR_DRV_Start(LPTMR0_IDX); // Start LPTMR
}
再在main()中调用lptrm_func(),则无法正确初始化LPTMR。
查API Reference,原型为:
lptmr_status_t LPTMR_DRV_Init ( uint32_t instance, lptmr_state_t *userStatePtr, const lptmr_user_config_t *userConfigPtr );
相同现象还有如下:
dspi_status_t DSPI_DRV_MasterInit ( uint32_t instance, dspi_master_state_t *dspiState, const dspi_master_user_config_t *userConfig) ;
dspi_status_t DSPI_DRV_MasterConfigureBus ( uint32_t instance, const dspi_device_t *device, uint32_t * calculatedBaudRate ) ;
只能在main()中才能正确初始化,一旦放在一函数并在main()中调用,即不成功。
代码为C:\Freescale\KSDK_1.2.0\examples\twrk64f120m\demo_apps\hello_world下的。IAR和Keil均试过。
|
|