Problem of core timer of BF533


I am using BF533 in a project . 

crystal oscillator clok = 24.576MHz

Set PLL at 20x. Core clock=24.576*20=491.5MHz 


The DMA1 interrupt runs at 192KHz by SPORT0 ,DMA5 interrupt runs at 192KHz too. 

192KHz I2S data in from SPORT0 and output via DMA5 by SPI0 .

Now i need to add a 384K pulse , I used core timer to generate this pulse. 

    *pTCNTL = *pTCNTL & 0xFFF7; // reset TINT (interrupt bit)

    *pFIO_FLAG_D |= PF4; 
    *pFIO_FLAG_D &= ~PF4; 

void Init_Core_Timer(void)
    *pTCNTL = 0x0007; // enables the timer and sets it to auto reload

    *pTPERIOD = 640;
    *pTCOUNT = 640;
    *pTSCALE = 1;

register_handler(ik_timer, CORE_TIMER_ISR);     


But, I can not get the right pulse . The pulse is disordered .

When i set  *pTPERIOD = *pTCOUNT = 24576; i can get 10KHz pulse .

When i set  *pTPERIOD = *pTCOUNT = 2458; i can get 100KHz pulse .

I can not get pulse over 192KHz, when *pTPERIOD ( *pTCOUNT) less than 1280, the pulse will disordered .

The interrupt of core timer should have high priority, it should not be affected by DMA interrupt .

Can anybody help me ? 

ADD *pIMASK|=0x00000020;
[edited by: Xuzhengyu at 8:44 AM (GMT -5) on 18 Feb 2021]