6.7 Serial/Parallel Interface Registers
The 820x serial to parallel interface (SPI) can be used to connect the 820x to an external
flash. The host can read/write the flash data through PCIe memory write/read SPI
registers. Figure 6-3 illustrates how the 820x may be connected to a flash device.
Figure 6-3. SPI Example Usage
The following flash devices are recommended:
Silicon Storage Technology: SST25VF032B 32 Mbit SPI Serial Flash
Spansion S25FL128P
6.7.1
SPI Register Operation flow
Prior to configuring any other SPI registers, it is necessary to set the SPI Enable Register.
The registers Flash Command Configuration Register 0 and Flash Command Configuration
Register 1 are set once during initialization by the host software. Setting the SPI Command
Address Register will trigger the 820x SPI module to process the current SPI command.
The following diagram illustrates the process flow for a flash operation.
820x – Data Sheet, DS-0157-D
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