Samsung SC32442B54, User Manual

Page: 482 / 647

SC32442B 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 with TAGD bit set.
2. Read 2 times for dummy byte pull out.
3. SPI is configured as DMA start with SMOD bits.
4. DMA is configured properly.
5. SPI receives 1byte data from card.
6. SPI requests DMA service.
7. DMA receives the data from the SPI.
8. Write data 0xFF automatically to SPTDATn.
9. Return to Step 6 until DMA count becomes 0.
10. SPI is configured as polling mode with SMOD bits.
11. If SPSTAn’s READY flag is set, then read the last byte data.
Note:
Total received data = the first 2 data in polling mode + DMA TC the last data in polling mode (Step
11).
The first two DMA received datas are dummy and the user can neglect it.
The last data can be neglected