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I have a problem with interrupts on the C5402 DSK. I use the IDLE 1 instruction to wait until a BRINT1 interrupt occurs from the AD50 codec, indicated by IFR@0h. When this occurs, the program does not jump to vector table and hence to the ISR, instead it loops around and waits for the next interrupt to occur. At the time of the interrupt, INTM=0 and IMR@0h. If I comment out the IDLE 1 instruction and replace it with INTR 26 to force it a BRINT1 interrupt, it jumps to the vector table and executes the ISR okay. Does anyone know what would cause the IDLE 1 to not jump to ISR apart from the obvious ie. IMR bit for BRINT1 not set, and INTM=1 ? Note, my vector table is remapped to 0x80. Regards Maurizio Gencarelli Avoinics Engineer Royal Australian Air Force |
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C5402 DSK INTERRUPT PROBLEM
Started by ●November 5, 2001
Reply by ●November 5, 20012001-11-05
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Hello, I'm new to the newsgroup, but I have had some experience with these serial ports, and I have a theory about what's going on. If memory serves, the serial port receive interrupt occurs on a shift-register-to-DRR copy event. If the DRR has not been read since the serial port was enabled, there's a chance that there's data waiting to be read. If that's the case, there will be no subsequent copying of data from the shift register to the DRR until that data is read, and hence no interrupt event to vector you to your ISR. I had this problem with DMA synchronization events once. To fix it, I would always do an unconditional read from the serial port's DRR register to free the logjam immediately after enabling interrupts. This way I know there won't be a logjam in the serial port. Hope this helps, Dave Helsley -----Original Message----- From: [mailto:] Sent: Monday, November 05, 2001 5:18 AM To: Subject: [c54x] C5402 DSK INTERRUPT PROBLEM I have a problem with interrupts on the C5402 DSK. I use the IDLE 1 instruction to wait until a BRINT1 interrupt occurs from the AD50 codec, indicated by IFR@0h. When this occurs, the program does not jump to vector table and hence to the ISR, instead it loops around and waits for the next interrupt to occur. At the time of the interrupt, INTM=0 and IMR@0h. If I comment out the IDLE 1 instruction and replace it with INTR 26 to force it a BRINT1 interrupt, it jumps to the vector table and executes the ISR okay. Does anyone know what would cause the IDLE 1 to not jump to ISR apart from the obvious ie. IMR bit for BRINT1 not set, and INTM=1 ? Note, my vector table is remapped to 0x80. Regards Maurizio Gencarelli Avoinics Engineer Royal Australian Air Force _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: Send an email to To Post: Send an email to To Leave: Send an email to Archives: http://www.yahoogroups.com/group/c54x Other Groups: http://www.dsprelated.com ">http://docs.yahoo.com/info/terms/ |
