Dear all,
I've met a Confusion of SWT for MPC5744P in S32DS.For this part,the code involves 3 parts,
1.void SWTInit(void),
2.void SWTClear(void),
3.void FCCUInit(void),
as follows:
// 1
void SWTInit(void)
{
/* Provide a Key to unlock SWT configuraiton registers */
SWT_0.SR.R = 0xC520;
SWT_0.SR.R = 0xD928;
/* Wait for solf-lock bit */
while (SWT_0.CR.B.SLK == 0x1);
/* Enable SWT_0 */
SWT_0.CR.B.WEN = 0x1;
/* Set SWT timeout */
SWT_0.TO.R = 0x000FFFFF;
SWT_0.CR.R = 0xFF000101;//0xFF000315;//0xFF000101;
}// end of SWTInit
// 2
void SWTClear(void)
{
SWT_0.SR.R = 0x0000A602; // 向SR中写入0xA602和0xB480喂狗
SWT_0.SR.R = 0x0000B480;
}// end of SWTClear
// 3
void FCCUInit(void)
{
/* Unlock configuration */
FCCU.TRANS_LOCK.B.TRANSKEY = 0xBC;
/* provide Config state key */
FCCU.CTRLK.R = 0x913756AF;
/* enter config state - OP1 */
FCCU.CTRL.R = 0x1;
/* Verify if state change was sucessful */
while (FCCU.CTRL.B.OPS != 0x3); //operation status successful
#if LONG_RESET
/* Configure FCCU to react on NCF14 with long functional reset */
FCCU.NCFS_CFG[0].R = 0x20000000; //long functional reset reaction
#else
/* Configure FCCU to react on NCF with short reset */
FCCU.NCFS_CFG[0].R = 0x10000000;
#endif
FCCU.NCF_CFG[0].R = 0x4000;
//set up the NOMAL mode of FCCU
FCCU.CTRLK.R = 0x825A132B; //key for OP2
FCCU.CTRL.R = 0x2; //set the OP2 - set up FCCU into the NORMAL mode
while (FCCU.CTRL.B.OPS != 0x3); //operational status succesfull
}//FCCU_Init
In the MAIN fuction,call the functions like this:
int main(void)
{
int counter = 0;
xcptn_xmpl (); // Configure and Enable Interrupts
peri_clock_gating(); // Configures enabling clocks
PLLInit();
GPIOInit();
PITInit();
FCCUInit();
SWTInit();
for (;;)//Loop forever
{
counter++;
HandleDevice();
//SWTClear();
//FCCUClearFaults();
}
return 0;
}//end of main
In the main function,no matter call SWTClear or not ,the MCU does not reset.
But when I config the FCCU as
FCCU.NCFS_CFG[0].R = 0x4000;
then no mater call SWTClear or not, the MCU will reset time after time papidly,and the period does not depend on the register :
/* Set SWT timeout */
SWT_0.TO.R = 0x000FFFFF;
(I judge the MCU reset or not by a LED which is configed to be light on.When the LED stay light on,I think the MCU does not reset;when the LED bink,I think the MCU is reset again and again.)
I wonder is there anything wrong in my configuration,or is there any example of SWT for MPC5744P in S32DS.
I am looking forward to your reply！
