Rainbow Electronics AT75C220 - Manual (Page 121)

AT75C220
121
SPI: Serial Peripheral Interface
The AT75C220 integrates a serial peripheral interface
(SPI) that provides communication with external devices in master or slave mode. Typically it is used to connect to
external processors or serial Flash.
Figure 27. Serial Peripheral Interface Block Diagram
Note: After a hardware reset, the SPI pins NPCS[3:1] are not enabled by default and must be programmed via the PIOA controller.
Serial Peripheral Interface
APB
ACLK
ACLK/32
MISO MISO
MOSI MOSI
SPCK SPCK
NPCSS NPCSS
NPCS1 NPCS1
INT
Advanced
Interrupt Controller
NPCS2
NPCS3
NPCS2
NPCS3
Table 26. SPI Interface Pins
Pin Name Description Mode Function
MISO Master In/Slave Out Master
Slave
Serial data input to SPI
Serial data output from SPI
MOSI Master Out/Slave In Master
Slave
Serial data output from SPI
Serial data input to SPI
SPCK Serial Clock Master
Slave
Clock output from SPI
Clock input to SPI
NPCSS Peripheral Chip Select/
Slave Select
Master
Master
Slave
Output: Selects peripheral
Input: Low causes mode fault
Input: Chip select for SPI
NPCS[3:1] Peripheral Chip Selects Master Extra selects