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Hi, I'm working with C5441 DSPs and C5402 DSK. Here is the situation and the problem: There is a 2 Mbps multichannel link connected to MCBSP0. Interrupts RINT and XINT are used for reading and writing. I have to select ch0 and ch1 for writing, all other channels must be in hi-z mode (so another DSP can handle other channels). Hi-z mode at DX pins is enabled when MCBSP transmitter is in reset state. The problem is pulling it out of reset, because it takes a while and channels are delayed! I use external clock and frame synchronization. Is there any oher way to set hi-z mode on DX line? I couldn't find any other alternative. Thank you. Regards, Kruno |
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MCBSP reset
Started by ●October 28, 2002
Reply by ●October 28, 20022002-10-28
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Krunoslav Sekovanic- > I'm working with C5441 DSPs and C5402 DSK. > > Here is the situation and the problem: There is a 2 Mbps multichannel > link connected to MCBSP0. Interrupts RINT and XINT are used for > reading and writing. I have to select ch0 and ch1 for writing, all > other channels must be in hi-z mode (so another DSP can handle other > channels). Hi-z mode at DX pins is enabled when MCBSP transmitter is > in reset state. The problem is pulling it out of reset, because it > takes a while and channels are delayed! I use external clock and > frame synchronization. > > Is there any oher way to set hi-z mode on DX line? I couldn't find > any other alternative. Suggest to: 1) Use built-in TDM modes of McBSP and all DSP software agrees to TDM slot definition and timing. This would work among several C5441s or other C54xx devices using synchronous clock. 2) Use simple external logic to OR together Tx lines; DSP/processor/other device take turns to write and when it's not their turn they write 1's. This method does not depend on built-in TDM mode and is much faster to control then "Reset". Jeff Brower DSP sw/hw engineer Signalogic |
