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Discussion Groups | TMS320C54x | External Port Problems
Technical discussions about the TI C54x DSPs (including the c5401, c5402, c5402a, c5404, c5407, c5409, c5409a, c5410, c5410a, c5416, c5420, c5421, c5441, c549, c5470 and c5471).
External Port Problems - Deena Naidoo - Nov 7 7:38:00 2002
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Hi all ! I can write to the external port, but when I read from the same port address, my return value, is the last value I wrote to it. My ADC is connected to port8000, so if I write eg. 50h to the configuration register in the ADC, then when I read from port8000 I get 50h. :-( , I should be getting data! this is my code: volatile int x,y; volatile ioport int port8000; volatile ioport int port2; void main() { port2 = 0x80; /* enables external port */ port8000 = 0x0CAA; /* writes 0xCAA to external port */ delay(1000); /* Calls A delay routine */ y = port8000; /* reads from port8000 */ port2 = 0x00; /* disables external port */ /* prints data onto the screen using LOG */ delay(1000); /* delay*/ LOG_printf(&trace, "%x", y); } I would be gratefull for any kind of assistance! I'm using CCS version 2. I'm writing my code in C. THANKX! > My other E-Mail address is: |
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Re: External Port Problems - Graham Trott - Nov 8 14:21:00 2002
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I don't think this is a software problem. You don't say which hardware you're using but on the '5402 the data written to off-board memory is held on the data latches and reads back in again if nothing has replaced it. Sounds like your ADC isn't putting anything on the bus. -- GT ----- Original Message ----- From: "Deena Naidoo" <> To: <> Sent: Thursday, November 07, 2002 7:38 AM Subject: [c54x] External Port Problems Hi all ! I can write to the external port, but when I read from the same port address, my return value, is the last value I wrote to it. My ADC is connected to port8000, so if I write eg. 50h to the configuration register in the ADC, then when I read from port8000 I get 50h. :-( , I should be getting data! |
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