timer3_init.c

基于8051F单片机,实现1024点的FFT 用C 语言实现的.效果与FPGA实现相同.

#include "FFT_Code_Tables.h"
//-----------------------------------------------------------------------------
// TIMER3_Init
//-----------------------------------------------------------------------------
//
// Configure Timer3 to auto-reload at interval specified by <counts> (no
// interrupt generated) using SYSCLK as its time base.
//
void TIMER3_Init (int counts)
{
   char old_SFRPAGE = SFRPAGE;      // Save Current SFR page

   SFRPAGE = TMR3_PAGE;             // Switch to Timer3 Setup Page

   TMR3CN = 0x00;                   // Stop Timer3; Clear TF3
   TMR3CF = 0x08;                   // use SYSCLK as timebase

   RCAP3  = -counts;                // Init reload values
   TMR3    = 0xffff;                // set to reload immediately
   EIE2   &= ~0x01;                 // disable Timer3 interrupts
   TR3 = 0x01;                      // start Timer3

   SFRPAGE = old_SFRPAGE;           // restore SFRPAGE
}