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48 lines
848 B
C
48 lines
848 B
C
#include <stdint.h>
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#include <stdio.h>
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typedef struct {
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int lastClkVal;
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int pos;
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uint8_t cmd;
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uint8_t mem[32];
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} Rtc;
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static Rtc rtc;
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void rtcTick() {
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int x;
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for (x=0; x<3; x++) {
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rtc.mem[x]++;
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if (rtc.mem[x]!=0) return;
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}
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}
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int rtcCom(int en, int dat, int clk) {
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int ret=0;
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clk=clk?1:0;
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if (en) {
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rtc.pos=0;
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rtc.cmd=0;
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} else {
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if (clk!=rtc.lastClkVal && !clk) {
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if (rtc.pos<8 || (rtc.pos<16 && ((rtc.cmd&0x8000)==0)) ) {
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if (dat) rtc.cmd|=(1<<(15-rtc.pos));
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} else if (rtc.cmd&0x8000) {
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if (rtc.pos==8) {
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rtc.cmd|=rtc.mem[(rtc.cmd&0x7C00)>>10];
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}
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ret=((rtc.cmd&(1<<(15-rtc.pos)))?1:0);
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} else if (rtc.pos==15) {
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if ((rtc.cmd&0x8000)==0) rtc.mem[(rtc.cmd&0x7C00)>>10]=rtc.cmd&0xff;
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printf("RTC/PRAM CMD %x\n", rtc.cmd);
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}
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rtc.pos++;
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}
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}
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rtc.lastClkVal=clk;
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return ret;
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}
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