Software serial communication | | EmbeddedRelated.com

In a message dated 6/25/02 11:42:28 AM Eastern Daylight Time, b...@swipnet.se writes:

I need two serial communication ports from my 68hc11. Is it anyone who have tested to write a program for a serial port?

9600bps bitbanger for icc11v6 attached.....

//file bitbang.c //send ascii out pa7 at 9600 bps //June 25 2002 initial edit //32k turbo microstamp: //cpu: hc11ed0 9Mhz //regs: 0x0000-0x003f //512 bytes ram: 0x0040..0x01ff //32k rom: 0x8000..0xffff //stack: 0x01ff #define _SCI #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #include "hc11ed0.h" extern void _start(void); /* entry point in crt??.s */ extern char _bss_end; //---ascii equates---------------- #define ESC 0x1b #define CR 0x0d #define LF 0x0a #define CTLQ 0x11 //------vars in bss------- //unsigned char istack[64]; unsigned char c,n; unsigned char dispon; unsigned char del; unsigned char xirqflg; unsigned char *pt; unsigned char *pf; unsigned char *p; char teststring[80]; //--------------------- const char banner[]={"bitbang June 25 2002 q for cal menu\n"}; //--------------------- void _HC11Setup(void){ //init some hc11 regs CONFIG=0x04; //nocop DDRD=0x3a; //ss, sck, mosi, txd are outs, bit 5 disables modf SPCR=0x50; //spi enab, mstr, cpha, 1mhz (1.25 with 9.8 mhz xtal) TFLG2=0x40; //clr rti flg PACTL |=0x80; //ddra7 output } //---------------------- void initsci(void){ //init sci to 38400 char jnk; BAUD= 0x20; //0x20=38400 0x22=9600 baud 9MHz xtal (0x30=9600 8mhz xtal) SCCR2=0x0c; //tx,rx enable jnk=SCSR; jnk=SCDR; } //------------------------- void initvars(void){ //init vars strcpy(teststring,"The quick brown fox jumped over the lazy dog's back.\n"); } //---------------------- char kbhit(void){ //return nonzero if char in sci (polled version) return(SCSR & RDRF); } //---------------------- int getchar(void){ //wait for char while(!kbhit()){}; //wait return SCDR; } //---------------------- void putc(char c){ //dont add lf after cr while((SCSR & TDRE)==0){}; //wait SCDR=c; } //---------------------- int putchar(char c) { //adds lf after cr if(c=='\n'){ putc('\r'); } putc(c); return c; } //---------------------- void putnibhex(unsigned char c){ //output bin nib c in hex c+=0x30; //cvt to ascii if(c > 0x39) c+=7; //handle a-f putc(c); } //----------------------- void putbytehex(unsigned char c){ //output c as 2 hex chars unsigned char nib; nib=(c & 0xf0) >>4; putnibhex(nib); nib=c & 0x0f; putnibhex(nib); } //----------------------- void putwordhex(unsigned int w){ //ouput w as 4 hex chars putbytehex(w >> 8); //hi byte putbytehex(w); //lo byte } //---------------------- void gotoxy(int x, int y){ //ansi cursor positioning sequence ESC[y;xH putchar(ESC); putchar('['); printf("%d",y); putchar(';'); printf("%d",x); putchar('H'); } //---------------------- void clrscr(void){ //clear ansi terminal screen putc(ESC); putc('['); putc('2'); putc('J'); } //------debug subs----------- void dump256(unsigned char *n){ //dump 16 rows of 16 bytes unsigned char r,c; unsigned char *p, *pa, ch; p=n; printf("\n "); for(c=0; c<16; c++){ printf("%02x ",c); //header if(c==7) printf(" "); } printf("\n\n"); for(r=0; r<16; r++){ printf("%04x ",p); //print addr at beg of line pa=p; //remember p for ascii for(c=0; c<16; c++){ printf("%02x ",*p++); //print hex if(c==7) printf(" "); } for(c=0; c<16; c++){ ch=*pa++; if((ch > 0x20) && (ch !=0x0a) && (ch != 0x8a)) //if printing char printf("%c",ch); //print ascii else printf("."); if(c==7) printf(" "); } printf("\n"); } } //------------ unsigned char getche(void){ //get and echo a char char c; c=getchar(); putchar(c); return(c); } //------------ unsigned char gethex(void){ //return a hex char unsigned char b,c; b=0xff; //error return value c=toupper(getche()); if(isxdigit(c)) b=c-0x30; //if c ok, cvt ascii digit to binary if((c>='A') && (c<='F')) b-=7; //if c hexcvt ascii A to binary 10 return(b); } //------------- unsigned char getbyte(void){ //get 2 nibbles, return a binary byte unsigned char n1,n2; n1=gethex(); n2=gethex(); return((n1 << 4)+n2); } //------------- unsigned int getaddr(void){ //return addr unsigned int th,tl; th=getbyte(); tl=getbyte(); return((th << 8)+tl); } //------------------ void examine(void){ //ask for mem range and dump unsigned char *from; unsigned char c; printf("\nfrom:"); from=(unsigned char *)getaddr(); while(c!='q'){ dump256(from); printf("np or q..."); c=getchar(); if(c=='n') from+=0x100; if(c=='p') from-=0x100; } } //------------------ void deposit(void){ //ask for addr and data unsigned char *at; unsigned char c; unsigned char nh,nl; printf("\nat:"); at=(unsigned char *)getaddr(); while(1){ printf(" %02x ",*at); nh=gethex(); if(nh==0xff) return; nl=gethex(); if(nl==0xff) return; c=((nh << 4) | nl); *at++=c; } } //------------------ void fill(void){ //ask for mem range and fill char and fill unsigned char *from, with; printf("\nfrom:"); from=(unsigned char *)getaddr(); printf(" with:"); with=getbyte(); memset(from,with,256); } //------------------ void (* fn)(void); //fn prototype void dojsr(void){ //ask for addr, jsr to it unsigned char *to; printf(" to:"); to=(unsigned char *)getaddr(); fn=(void *)to; (*fn)(); //call function fn and returns } //----end of debug subs---------- //------------------- void delnms(int n){ //delay n ms char x; while(n--){ x=73; //empirically determined fudge factor while(x--); } } //------------------- void initxirq(void){ //enable xirq interrupt asm("tpa"); //ccr to a asm("anda #$bf"); //clear x bit in ccr asm("tap"); //a to ccr } //------------------ void initscreen(void){ clrscr(); puts(banner); } //---------------------- void del104us(void){ //delay 1 bit time at 9600 char x; x=6; while(x--); } //----------------------- void putaux(char c){ //bitbang c out pa7 at 9600bps 8,n,1,lsb first 104us/bit //1.5 bits=152us char b,msk; INTR_OFF(); //just for 1ms... msk=0x01; PORTA &= ~0x80; //start bit lo del104us(); //start bit bit time // PORTA |=0x80; //start bit hi for(b=0; b<8; b++){ //for 8 bits if(c & msk){ // if bit is 1 PORTA &= ~0x80; //pa7 lo }else{ PORTA |=0x80; //pa7 hi } msk <<=1; del104us(); //rest of 1 bit time } PORTA |=0x80; //pa7 hi for stop bit del104us(); //stop bit INTR_ON(); } //----------------------- void printaux(char *p){ //print string at p out aux char c; while(1){ c=*p++; if(c==0) break; putaux(c); } } //----------------------- void dotest(void){ //print test string till q char c; printf("sending test string q to quit\n"); while(c !='q'){ if(kbhit()){ c=getchar(); } printaux(teststring); delnms(1); } } //----------------------- void dou(void){ //print UUUs till q char c; printf("sending UUUs q to quit\n"); while(c !='q'){ if(kbhit()){ c=getchar(); } printaux("UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU"); delnms(1); } } //-------------------------- void debugmenu(void){ //debug cmds initscreen(); gotoxy(1,7); printf("bitbang cmds:\n"); printf(" t test string\n"); printf(" u UUUs\n"); printf(" r restart\n"); printf("Debug cmds:\n"); printf(" e examine\n"); printf(" d deposit\n"); printf(" f fill\n"); printf(" j jsr\n"); } //-------------------------- void debugswitch(char c){ //parse char from keyboard switch(c){ case 't': dotest(); break; case 'u': dou(); break; case 'r': _start(); break; case 'e': examine(); break; case 'd': deposit(); break; case 'f': fill(); break; case 'j': dojsr(); break; default: debugmenu(); } } //----------------------- void rtloop(void){ //real time loop char c; printf("rtloop q to quit\n"); while(c != 'q'){ if(kbhit()){ c=getchar(); } printaux(teststring); delnms(1); } //while } //----------------- void main(void){ //main program char c; initsci(); initscreen(); initvars(); // _NewHeap(&_bss_end,&_bss_end+0x58); //create heap for malloc // initxirq(); // rtloop(); while(1){ //main loop debugmenu(); printf("\n>"); //prompt for input c=getche(); debugswitch(c); } } //------interrupt handlers----------------------- #pragma interrupt_handler DUMMY_ENTRY void DUMMY_ENTRY(void){ puts("unexpected interrupt!"); while(1){}; } #pragma interrupt_handler xirqhdr void xirqhdr(void){ //you have 10 ms 5v holdup to burn params in eeprom // xirqflg++; // if(xirqflg==1){ // powerfailrom(); // while((PORTA & 0x01)==0){ //pa0 lo? // delnms(500); // } // asm("jmp __start"); //reloads stack pointer // }else{ // printf("xirq %d!\n",xirqflg); // } puts("xirq!"); while(1){}; } #pragma interrupt_handler scihdr void scihdr(void){ //sci puts("sci!"); while(1){}; } #pragma interrupt_handler spihdr void spihdr(void){ //spi puts("spi!"); while(1){}; } #pragma interrupt_handler irqhdr void irqhdr(void){ //unvectored irq puts("irq!"); while(1){}; } #pragma interrupt_handler tofhdr void tofhdr(void){ //tof puts("tof!"); while(1){}; } #pragma interrupt_handler swihdr void swihdr(void){ //swi puts("swi!"); while(1){}; } #pragma interrupt_handler rtihdr void rtihdr(void){ //count 65536 tics of 4.096ms TFLG2=0x40; //clear interrupt flag // tics++; //bump tics // asm(" sts %tmpstk"); // if(tmpstk<minstk) minstk=tmpstk; } #pragma interrupt_handler illophndlr void illophndlr(void){ //illegal opcode handler... dumps regs puts("illop!"); while(1){}; // asm(" sts _pf"); //store stack pointer in a dedicated global variable // asm(" lds #_istack+63"); // pf+=5; //get past 5 bytes on stack to see cc // puts("\ncc b a x y pc sp"); // for(n=0; n < 9; n++){ // putbytehex(*pf++); // putc(' '); // } // putwordhex((unsigned int)pf); //unrolled sp // putchar('\n'); // c=getchar(); // asm("jmp __start"); //reloads stack pointer } #pragma interrupt_handler cophndlr void cophndlr(void){ puts("cop!"); while(1){}; } //-----reset vectors in end of rom-------------------- #pragma abs_address:0xffd6 void (*interrupt_vectors[])(void)={ scihdr, //SCI spihdr, //SPI DUMMY_ENTRY, //PAIE DUMMY_ENTRY, //PAO tofhdr, //TOF DUMMY_ENTRY, //TOC5 DUMMY_ENTRY, //TOC4 DUMMY_ENTRY, //TOC3 DUMMY_ENTRY, //TOC2 DUMMY_ENTRY, //TOC1 DUMMY_ENTRY, //TIC3 DUMMY_ENTRY, //TIC2 DUMMY_ENTRY, //TIC1 rtihdr, //RTI irqhdr, //IRQ xirqhdr, //XIRQ swihdr, //SWI illophndlr, //ILLOP cophndlr, //COP DUMMY_ENTRY, //CLM _start //RESET }; #pragma end_abs_address //--------eof-------------

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Discussion Groups | | Software serial communication

Software serial communication - Bj�rn Gullander - Jun 25 10:53:00 2002

RE: Software serial communication - Peter Mackel - Jun 25 11:05:00 2002

Re: Software serial communication - Author Unknown - Jun 25 12:38:00 2002