Hello All,
I am using DM355 to send a chuck 4Kb of data using the DMA over the SPI
bus (mp is DM355).
The DMA is allocated for SPI channel 1 to the TX and RX events (event 14
and 15 are used).
The DMA is configured, in ASYNC mode. With SPI data register "SPIDAT1"
as the destination address. And a constant buffer is used as source.
Since I need the destination address needs to be unchanged, i set the
DAM bit to 1, and set the fifo width to 0, and sybcdim bit to 0 (this is
for ASYNC).
The SPI is configured to DMA mode by setting the SPIENA bit in SPIGCR1
register. DMA enable bit in SPIINT is set to start DMA.
When we set the shadow register to transmit data, we see that a relevant
clock is generated, but the MOSI is always low (to what ever data we
give) and goes high immediately after the last clock cycle.
When I am giving the ACNT is 1, BCNT is 4096, CCNT is 1, I did not get
an interrupt at all.
If I make the CCNT as 0, I see that I get the interrupt properly, though
i am not sure for this.
Could any one let me know what could be the reason behind the data out
line being low always?
Further what would be relevant values of the ACNT and BCNT and CCNT?
If anyone faced similar issue, please provide your valuable comments.
Thanks a lot in advance.
Regards,
Prabhaharan.R
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