How to use ADuC812 SPI

We are developing a project with ADuC812 in Federal University of Campina
Grande, and I wish to communicate two microconverters using the SPI. I have
some problems becouse with the flag ISPI becouse the flag don't change in
the
end of the transmission. Is necessary to use any interrupt routine for to
use
the flag ISPI? I need more information about this problem. I am sending my
code
used for transmit a caracter C and to monitore the change in flag ISPI. I
noted
that the flag don't change. Please look my code, is it wrong?
Send me some information, and if possible change the code.
If possible, answer me how I may to transmit a byte in a master(
micriconverter) for a slave(microconverter).


Sincerely,
Jaidilson Jó.

//Master

#include <aduc812.h>
#include <stdio.h>
#define SPICON_MR 0x33

sbit P3_5 = 0xB5;
sbit P3_4 = 0xB4;

int i;

void main ()
{
P3_5 = 1;

// Serial
SCON = 0x50;
TMOD = 0x20;
TR1 = 1;
TH1 = 0xFD;

IE2 = 0x01;
IE = 0x81;
TCON = 0x01;
IT0 = 1;
SPICON = SPICON_MR;

P3_5 = 0;
P3_4 = 0;

SPIDAT = 'C'; //writing a character C for to transmit

while((SPICON & 0x80) == 0)
{
TI=0;
SBUF='\n';
while(TI != 1){}
printf("%\n",SPICON);
while(TI!=1) { }
}

TI=0;
SBUF='\n';
while(TI != 1){}
printf("%\n",SPICON);
while(TI!=1) { }

P3_4 = 1;
P3_5 = 1;


}

Hello André,

I'm using the ADuC834, but I expect, that the configuration and usage of the SPI is the same as for the ADuC812.

Your initialisation seems to be o.k. - just take care, that the clock, polarity and phase settings match the requirements of your slave device. For the following SPI routine, you will not need to enable the interrupt. The routine can be used for sending and reading bytes. To read a byte just send a dummy character.

UI8 SPI_char( const UI8 c )
{
    ISPI = 0;
    SPIDAT = c;
    while( !ISPI )
    {
        ; // do nothing but wait
    }
    return( SPIDAT );
}

Hello all,

I put your code in my aplication:
#include <stdio.h> // declarations for I/O functions
#include <ADuC812.h> // 8052 & ADuC812 predefined symbols

// Variables globales
bit flag_int=0; // Flag de la interrupcion
unsigned char dato=0;

sbit SS = P3^5; /* SFR for P3.5 */

// Prototipos de funciones
void spiTx(unsigned char txDat); // Transmit a byte data over the SPI
unsigned char SPI_char( unsigned char c );

//___________________________________________________________________
// INTERRUPT SERVICE ROUTINE

void spi_int () interrupt 7 { // ISPI*8+3 = 59dec = 3bhex = ISPI

SS= 1; // complement SS (P3.5 on eval bd.)
dato=dato+1;
}

/* END OF INT0 INTERRUPT ROUTINE */
//____________________________________
//___________________________________________________________________
// INTERRUPT SERVICE ROUTINE

void int0_int () interrupt 0 { // int0*8+3 = 0dec = 3hex = IE0

flag_int=1; // Flag de detección INT0 externa
P3 ^= 0x10; // complement LED (P3.4 on eval bd.)
dato=dato+1;
}

/* END OF INT0 INTERRUPT ROUTINE */
//___________________________________________________________________
// MAIN PROGRAM

void main (void)
{


/* CONFIGURE SPI */

/* SPICON */

SPE = 1; // SPI interface enable
SPIM = 1; // SPI master mode operation
CPOL = 0; // SPI CLOCK idles High
CPHA = 0; // SPI leading SCLOCK edge to transmit data
SPR1 = 1; // SPI clock rate SPR1 0 SPR0 0 for Fosc/4
SPR0 = 1;

/* CONFIGURACION DE LAS INTERRUPCIONES */

EX0=1; // 1.- Habilitación Interrupcion externa 0
PX0=1; // 2.- Interrupción externa 0 de alta prioridad
IT0=1; // 3.- Interrupción externa 0 activa por flanco de bajada

IE2=1; // Interrupcion Interrupcion SPI de fin de transmision


EA=1; // Se permiten todas las interrupciones anteriormente programadas

/* WAIT FOR INTERRUPTS */
while (1)

{

// while (flag_int)
// {
// spiTx(dato); // Manda dato por SPI
SPI_char(2);
// flag_int=0; // Restauro el flag de la interrupcion

// }


} // endless loop

}

void spiTx(unsigned char txDat) // Transmit a byte data over the SPI
{
ISPI = 0; // Clear ISPI bit
SS=0;
SPIDAT = txDat;
while(!ISPI); // Wait until tx complete
}

unsigned char SPI_char( unsigned char c )
{
ISPI = 0;
SS=0;
SPIDAT = c;
while( !ISPI )
{
; // do nothing but wait
}
return( SPIDAT );
}

I able to program clock and togle a port(I saw in osciloscope) but data does not flow thought MOSI line...

Can anybody help me?