Samsung S3C2440A - Manual (Page 475)

S3C2440A RISC MICROPROCESSOR SPI
22-5
TRANSMITTING PROCEDURE FOR DMA
1. SPI is configured as DMA mode.
2. DMA is configured properly.
3. SPI requests DMA service.
4. DMA transmits 1byte data to the SPI.
5. SPI transmits the data to card.
6. Return to Step 3 until DMA count becomes 0.
7. SPI is configured as interrupt or polling mode with SMOD bits.
RECEIVING PROCEDURE FOR DMA
1. SPI is configured as DMA start with SMOD bits and TAGD bit set.
2. DMA is configured properly.
3. SPI receives 1byte data from card.
4. SPI requests DMA service.
5. DMA receives the data from the SPI.
6. Write data 0xFF automatically to SPTDATn.
7. Return to Step 4 until DMA count becomes 0.
8. SPI is configured as polling mode with SMOD bits and clear TAGD bit.
9. If SPSTAn’s READY flag is set, then read the last byte data.
Note: Total received data = DMA TC values + the last data in polling mode (Step 9).
The first DMA received data is dummy and the user can neglect it.