I am using the simulator of the uvision2. According to the debugger the value of c doesn't change (I am using the serial peripheral) and the debugger never execute the Start_bit = 1; even though the SBUF = 0x46.
char c ; void SerialPort(void) interrupt 4 using 2 { if (RI == 1) { c = SBUF; if(SBUF==0x46) Start_bit = 1; RI = 0; } }
This is the extention of the first interrupt function, but steel according to the simulator debugger ArrLen and chr stay with their init values after the assignment ArrLen = SBUF; void SerialPort(void) interrupt 4 using 2 { if (RI == 1) { if(ArrLenFlag==0) // The first value. { ArrLen = SBUF; ArrLenFlag = 1; } else { if(SBUF=='S') // The start char. { Start_bit = 1; SaveData(1000); SaveData(1000); } else { chr = SBUF; SaveData(chr) // Save the data. } } RI = 0; } } Thank for your help Kobi
what is IE ? what id SCON ?
The SCON = 0x50; IE = 1; Thank you very much for your help
IE = 1 guarantees that you will not get any interrupts. Have a look at <a href="" target="_blank">http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf">the proframmers reference manual</a> and set the SFRs ciorrectly. Erik
Hi I finnaly understood that the local variable is changed to zero and didn't stay at zero (which means that it doesn't succcefuly read the SBUF???). here are all my init values.
TMOD = 0x20; TH1 = 0xFB; // baud ~19200; TR1 = 1; SCON = 0x50; IE=0x90; EA = 1; ES = 1; REN = 1; RI = 0; void SerialPort(void) interrupt 4 using 2 { while(!RI) { if(ArrLenFlag==0) { ArrLen = _getkey (); ArrLenFlag = 1; } else { if(_getkey()=='S') { Start_bit = 1; SaveData(1000); SaveData(1000); } else { chr = _getkey (); SaveData(chr); } } RI = 0; TI = 0; } }