Programming Model
21-42
ADSP-BF50x Blackfin Processor Hardware Reference
Using DMA
The procedure is as follows:
1. Write the
RSI_ARGUMENT
register with the cards RCA. The 16-bit
RCA should be written to the upper 16-bits of the
RSI_ARGUMENT
register.
2. Write the
RSI_COMMAND
register with the
SELECT/DESELECT_CARD
command, configuring the command path state machine to expect
a short response by setting
CMD_RESP
and clearing
CMD_L_RESP
. The
response type is R1b.
3. Wait for the
CMD_RESP_END
indication within the
RSI_STATUS
register, and clear the status bit once detected via the
RSI_STATUSCL
register.
4. Ensure that the device is not busy and no errors occurred by
verifying the response contained in
RSI_RESPONSE0
.
5. Configure the DMA channel assigned to the RSI controller. Write
DMAx_START_ADDR
with the address of the first byte of where the
received data is to be stored. The
DMAx_X_COUNT
register should be
set to 128 and the
DMAx_X_MODIFY
register to 4. The
DMAx_CONFIG
register should be set for DMA enable (a word size of 32-bits and
direction set to memory write).
6. Write the number of bytes to be transferred to the
RSI_DATA_LGTH
register. This will be 512 bytes for a single block.
7. Write the appropriate timeout value for a read operation to the
RSI_DATA_TIMER
register.
8. Write the source start address to the
RSI_ARGUMENT
register. The
supplied address must be aligned to a 512-byte boundary if mis-
aligned accesses are not enabled and the card is not a high-capacity
SD card or sector-addressable MMC card.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...