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Hi all! I'm trying to configure a McBSP transfer between two C6202 using DMA events both to transmit and receive data. The process is ok, except that data received is shifted by two bytes (first two values are nonsense). I'm I loosing something? If it helps, I include the config for both ports RX TX McBSP: McBSP: SPCR = 0x00000000 SPCR = 0x00000000 RCR = 0x00020000 RCR = 0x00020000 XCR = 0x00020000 XCR = 0x00020000 SCGR = 0x20000007 SCGR = 0x20000007 MCR = 0x00000000 MCR = 0x00000000 RCER = 0x00000000 RCER = 0x00000000 XCER = 0x00000000 XCER = 0x00000000 PCR = 0x00000A00 PCR = 0x00000A00 DMA: DMA: PRI = 0xC3681240 PRI = 0x33701210 SEC = 0x00080080 SEC = 0x00080080 Thanks in advance ''~`` ( o o ) +-----------------.oooO--(_)--Oooo.-----------------+ | | | PABLO FRAILE | | .oooO | | ( ) Oooo. | +--------------------\ (----( )-------------------+ \_) ) / (_/ |
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McBSP with DMA
Started by ●May 7, 2002
Reply by ●May 7, 20022002-05-07
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Hi pablo, While working with the TMS320C6711 there was an issue we had with the EDMA and MCBSP's. It is rather subtle. Since I am not familiar with the C6202, I do not know if the information below is relevant. Nonetheless here it is Basically, we found issues in handling (E)DMA transfers to off chip memory with 4-way caching enabled (i.e. all of the on chip memory was configured as cache). The issue was likely that a DMA to an off-chip memory location would produce a cache mis-match which could cause a replacement of the DMA'd data when the cache controller wrote back to off-chip memory. Turning off cache solves the problem. An alternate route we chose however, was to configure on-chip memory as 3/4 cache and 1/4 SRAM and put our DMA buffers in SRAM. -Brad -----Original Message----- From: pablo fraile [mailto:] Sent: Tuesday, May 07, 2002 12:26 AM To: C6x@Yahoogroups. Com Subject: [c6x] McBSP with DMA Hi all! I'm trying to configure a McBSP transfer between two C6202 using DMA events both to transmit and receive data. The process is ok, except that data received is shifted by two bytes (first two values are nonsense). I'm I loosing something? If it helps, I include the config for both ports RX TX McBSP: McBSP: SPCR = 0x00000000 SPCR = 0x00000000 RCR = 0x00020000 RCR = 0x00020000 XCR = 0x00020000 XCR = 0x00020000 SCGR = 0x20000007 SCGR = 0x20000007 MCR = 0x00000000 MCR = 0x00000000 RCER = 0x00000000 RCER = 0x00000000 XCER = 0x00000000 XCER = 0x00000000 PCR = 0x00000A00 PCR = 0x00000A00 DMA: DMA: PRI = 0xC3681240 PRI = 0x33701210 SEC = 0x00080080 SEC = 0x00080080 Thanks in advance ''~`` ( o o ) +-----------------.oooO--(_)--Oooo.-----------------+ | | | PABLO FRAILE | | .oooO | | ( ) Oooo. | +--------------------\ (----( )-------------------+ \_) ) / (_/ _____________________________________ 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/c6x Other Groups: http://www.dsprelated.com ">http://docs.yahoo.com/info/terms/ |
