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Hi, We are in the process of upgrading our DSP from C549 to C5409 and have a few questions that we need to sort out first before starting the design. i) Can the 5409 DMA transfer data from external memory between 8000h to FFFFh to the McBSP serial port (tx and rx) ? The data sheet (SPRS082C Apr 1999 pg 25) says that it cannot transfer from external memory to peripheral or vice versa. However it also says that 2 channel is available for external accesses. So it is really possible ? If not is there any other way to DMA from external memory to the McBSP ? ii) If the McBSP is connected to a 128 time slot PCM bus (shared between another DSP), can I transmit more than 32 time slot and put the DX pin tri-state for the rest of the timeslot ? The datasheet says that it can transmit max 32 time slot only (pg. 20) Can I set the frame length (XFRLEN1) to 64 so that the DX pin is driven from time slot 0 to timeslot 63 and go tri-state for timeslot 64 to timeslot 127 ? I don't intend to use the MCR registers since it is very troublesome. iii) Is it possible to transmit starting from timeslot 64 up to timeslot 127 >without CPU intervention to the PCM bus ? The DX pin should not be driven from timeslot 0 to timeslot 63. Once again usage of MCR is not preferred. Regards, Hew |
C5409 McBSP and DMA
Started by ●June 30, 2000
