setup_555.c

mpc564 时钟中断 时钟中断

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#include "mpc555.h"
#include "m_tpu3.h"

void setup_555(void)
    {

    struct TPU3_tag *tpua = &TPU_A;         /* pointer for TPU_A */
    struct TPU3_tag *tpub = &TPU_B;         /* pointer for TPU_B */
    struct UIMB_tag *uimb = &UIMB;          /* pointer for UIMB */

/* setup TPUMCR: clear SUPV bit, setup TCR1P and TCR2P prescalers */

    tpua->TPUMCR.R = (tpua->TPUMCR.R & 0xFF7F) | 0x4040;    /* set TPUMCR for TPU3_A                                            */

    tpub->TPUMCR.R = (tpub->TPUMCR.R & 0xFF7F) | 0x4040;    /* set TPUMCR for TPU3_B                                            */

/* derive TCR1 input of 1MHz from a 40MHz system clock as follows: */
/*      setup TPUMCR3: EPSCK and EPSCKE bits for TPU_A and TPU_B   */

    tpua->TPUMCR3.R = 0x0044;   /* set TPU A enhanced prescalar to divide by 40 */

    tpub->TPUMCR3.R = 0x0044;   /* set TPU B enhanced prescalar to divide by 40 */

    uimb->UMCR.R = 0x0;         /* set IMB3 BUS speed = U BUS speed (MPC555 default is 1/2) */

    setup_ext_int();            /* set up MPC555 external interrupts */

    tpua->TICR.R = 0x0230;      /* set up IRQ level 2 in TPU Interrupt Config Reg */

    }