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Greetings, I'm receiving a constant interrupt when I turn on the Transmit interrupt. When I disable the transmitter I do not get the interrupt so I think my IRQs and priority are right. I am opperating the sport with an internal clock/ internal frame sync/ DITFS = 0 only frame when there is data. and Late frame sync. I'm getting a constant interrupt as soon as I turn on the transmitter whether I transmit a single 16bit word or not. I would like a single interrupt after the TX buffer empties and is ready for the next word. Any Ideas? thanks JH |
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EZkit 2191 SPORT TX Interrupt
Started by ●June 12, 2003
Reply by ●June 13, 20032003-06-13
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--On Thursday, June 12, 2003 7:58 PM +0000 hillho <> wrote: > I'm getting a constant interrupt as soon as I turn on the transmitter > whether I transmit a single 16bit word or not. I'm not familiar with the 2191, but it sounds like the interrupt is level-triggered by the condition of TX register empty, not edge-triggered as you might desire. This is pretty similar to the way many UART's work. What do you do in your ISR? You could use a boolean to remember if this is the first invocation (before anything has been transmitted yet) and load the first word to send if so, and do nothing else until the next time. |
Reply by ●June 13, 20032003-06-13
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Read Page 9 of chapter 13 of the ADSP-219x/2191 DSP Hardware Reference,
which can be downloaded from the AD website. The extract from the page: "Setting TSPEN causes an immediate assertion of a SPORT TX interrupt, indicating that the TX data register is empty and needs to be filled." If you read over this chapter the SPORT operation should make more sense. Cheers Brett hillho wrote: Greetings, I'm receiving a constant interrupt when I turn on the Transmit interrupt. When I disable the transmitter I do not get the interrupt so I think my IRQs and priority are right. I am opperating the sport with an internal clock/ internal frame sync/ DITFS = 0 only frame when there is data. and Late frame sync. I'm getting a constant interrupt as soon as I turn on the transmitter whether I transmit a single 16bit word or not. I would like a single interrupt after the TX buffer empties and is ready for the next word. Any Ideas? thanks JH _____________________________________ 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 a...@yahoogroups.com To Post: Send an email to a...@yahoogroups.com To Leave: Send an email to a...@yahoogroups.com Archives: http://groups.yahoo.com/group/adsp Other Groups: http://www.dsprelated.com/groups.php3 ">http://docs.yahoo.com/info/terms/ --
Brett Olsen
Senior DSP Design Engineer
Tait Electronics Ltd 175 Roydvale Avenue Christchurch New Zealand Phone: (64) (3) 357 0766
Fax: (64) (3) 359 4632 Email: b...@tait.co.nz Post: PO Box 1645, Christchurch, NZ |
Reply by ●June 20, 20032003-06-20
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JH, My guess is you are setting the interrupt latch rather then unmasking the interrupt bit in IMASK. As you say the interrupt occurs whether or not you transmit a word. You might also have another IO device mapped to that priority. In that case, the other device may be causing your ISR to run. What rev silicon did you get with you EZlite board?? Regards TD --- In , "hillho" <hillho@y...> wrote: > Greetings, > > I'm receiving a constant interrupt when I turn on the Transmit > interrupt. When I disable the transmitter I do not get the interrupt > so I think my IRQs and priority are right. I am opperating the sport > with an internal clock/ internal frame sync/ DITFS = 0 only frame > when there is data. and Late frame sync. > > I'm getting a constant interrupt as soon as I turn on the transmitter > whether I transmit a single 16bit word or not. > > I would like a single interrupt after the TX buffer empties and is > ready for the next word. > > Any Ideas? > > thanks > JH |
