ST72334N4 & SCI

ylltkl · ‎2006-01-25

Posted on January 26, 2006 at 08:22

ST72334N4 & SCI

ylltkl · ‎2006-01-22

Posted on January 23, 2006 at 04:17

HI,

Currently I using the ST72334N4 and I face a problem related to SCI. I wish to connect the ST72334N4 to PC (Visual Basic) via Uart and the baud rate is 19200, no parity, 8 bit data, 1 start and 1 stop bit. Below is the setting for St72334 I used. The ST72334 Fosc is 8MHz and using SCI receive interrupt.

SCICR1=0x00;

SCICR2=0x00;

SCIBRR=0x00;

SCIERPR=26;

SCIETPR=26;

//set as SCI receive, interrupt enable

PEDR &= 0xEF;

PEDR|=0x03;

SCICR2 = 0x24;

On the PC side, I am using Visual Basic MSCOMM control and set the property as ''19200,N,8,1''. I sent a byte of data from PC to ST72334 using MSCOMM1.OUTPUT=chr(x). x is a value from 0-255.

I notice that for x=0-128, St72334 can receive the byte correctly. For x=129-255, ST72334 receive the byte wrongly, always receive ''0''.

May I know why this happen and how do I solve this problem?

Please help ASAP coz I am now stuck and cannot continue the development.

Thanks.

regards,

St72334 user.

:(

wolfgang2399 · ‎2006-01-25

Posted on January 26, 2006 at 08:22

Hi,

did you still record the transferred data signals with an oscilloscope? Are they correct?

Of my experience I may not beleave, that the ÂµC doesn't work correctly in your configuration.

But: What sense does it make to clear port PE4 and to set PE0 (TD0) and PE1 (RDI)????

btw.: You can fix exactly the same baudrate using the prescaler of the Baud Rate Register (BRR) SCP=13 and SCT = SCR = 2.

Regards

WoRo