Hello All,
I am using MSC1212Y5 Microcontroller. It has two serial ports. I have directed printf to second serial port by changing putchar.c file in keil library. At the same time I am using first port for transmitting single characters only. i.e. 'T' ..'R'..etc. But whenever i try to use printf for both ports, of course by disabling one port for some time then it is not working..it sends data to only second serial port.
ohh sorry I will write the exact code here.
//Program to test serial port of Texas Instruments MSC1212Y5 Controller // BaudRate: 9600 //Important note: When using Printf disable INTR driven transfer
#include "reg1212.h" #include "stdio.h"
#define SET 1 #define RESET 0
unsigned char ch_0,ch_1,Disp_Flag; //character to rcv
void init_port(); //Inits UART0 using timer2 at Baud rate of : void send_out(unsigned char); void init_port_timer1(); void init_port1(); void send_out1(unsigned char out1);
void main() { init_port(); init_port1();
while(1) {
ES0=1;
TI_0=1; printf("I am Port0"); TI_0=0; ES0=0;
ES1=1; TI_1=1; printf("I am port1"); TI_1=0; ES1=0;
}
void init_port() { P3DDRL|=0x07; //Define port3 for alternate fucntions P3.0=RXD and P3.1=TXD
SCON=0x50; //Rcv enable mode2 1 start bit 8Data bits 1 Stop bit. RCAP2H=0xFF; //To generate baud rate of 9600 ..clk 25Mhz RCAP2L=0xAD; T2CON=0x34; //timer2 enabled for Baud generation of both Rx and Tx ES0=1; //Enable serial0 INTR // EA=1; TI_0=1; //To initiate first character Xmission
/* void init_port_timer1() //Timer1 to generate baud rate for UART0 { SCON=0x50; TMOD=0x20; //Mode2 8bit autorld TH1=0xF9; //For 9600 with clk 25Mhz TR1=1; //Run timer ES0=1; EA=1; //TI_0=1; }*/
void serial_Intr(void)interrupt 4 { if(RI_0==1) { ch_0=SBUF0; RI_0=0; }
/* else if(TI_0==1) { if(!Disp_Flag) goto down; TI_0=0; down: _nop_(); }*/ }
void send_out(unsigned char out) { SBUF0=out; while(TI_0==0); //Wait while char is Xmitted TI_0=0; }
void init_port1() { SCON1=0x50; TH1=0XEC; //19200 Baud rate CKCON|=0x10; TMOD|=0X20; //Timer1 mode 2 TR1=1; ES1=1; TI_1=1; EA=1;
void send_out1(unsigned char out1) {
SBUF1=out1; while(TI_1==0); //Wait while char is Xmitted TI_1=0;
void serial_Intr1(void)interrupt 6 { if(RI_1==1) { ch_1=SBUF1; RI_1=0; }
else if(TI_1==1) { //if(!Disp_Flag) goto down; TI_1=0; //down: _nop_(); } }
********************************************************************************* And the Putchar.C file after modification is as follows. ******************************************************************************** #include <reg51.h>
#define XON 0x11 #define XOFF 0x13
sfr SBUF1 = 0xC1; /* SBUF for SIO 1 */ sbit RI_1 = 0xC0; /* RI for SIO 1 */ sbit TI_1 = 0xC1; /* TI for SIO 1 */ sfr SCON1 = 0xC0; /* SCON for SIO 0 */
sfr SBUF0 = 0x99; sbit RI_0 = 0x98; sbit TI_0 = 0x99; sfr SCON0 = 0x98;
/* * putchar (full version): expands '\n' into CR LF and handles * XON/XOFF (Ctrl+S/Ctrl+Q) protocol */ char putchar (char c) {
if (c == '\n') { if (RI_1) { if (SBUF1 == XOFF) { do { RI_1 = 0; while (!RI); } while (SBUF1 != XON); RI_1 = 0; } } while (!TI_1); TI_1 = 0; SBUF1 = 0x0d; /* output CR */ } if (RI_1) { if (SBUF1 == XOFF) { do { RI_1 = 0; while (!RI); } while (SBUF1 != XON); RI_1 = 0; } } while (!TI_1); TI_1 = 0; return (SBUF1 = c); }
#if 0 // comment out versions below
/* * putchar (basic version): expands '\n' into CR LF */ char putchar (char c) { if (c == '\n') { while (!TI_1); TI_1 = 0; SBUF1 = 0x0d; /* output CR */ } while (!TI_1); TI_1 = 0; return (SBUF1 = c); }
/* * putchar (mini version): outputs charcter only */ char putchar (char c) { while (!TI_1); TI_1 = 0; return (SBUF1 = c); }
#endif
i wont do it like that!
say what usart you want to use b4 u use printf
I want to use the both USARTS for with printf statement.
If you want to use both USARTs alternatingly, then you will have to add a software mux layer.
You may create a new function: switch_to_usart(port);
This could affect a global variable used by your modified putchar() to decide if the data should be put into one or the other USART, or - if you use interrupt-based transmission - which transmit buffer to put the data in.
Basically the switch_to_usart(port) would redirect "stdout" to different hardware.
I didn't get you.Please tell in detail. Actually I have modified the file Putchar.c which is used by Printf directly to the RI_1 and TI_1..Does this make problem??
You have to modify putchar() to do:
if (output == UART1) { ... } else { ... }
and you have to switch output to specify UART1 or UART2 depending on which serial port that should get the data from printf().
Each individual branch has to make use of the registers for that specific UART.