Rainbow Electronics 71M6542G - Manual (Page 76)

76 © 2008–2011 Teridian Semiconductor Corporation v1.1
Table 64: SPI Registers
Name Location Rst Wk Dir Description
EX_SPI 2701[7] 0 0 R/W SPI interrupt enable bit.
SPI_CMD SFR FD[7:0] – – R SPI command. The 8-bit command from the bus master.
SPI_E 270C[4] 1 1 R/W
SPI port enable bit. It enables the SPI interface on pins
SEGDIO36 – SEGDIO39.
IE_SPI SFR F8[7] 0 0 R/W SPI interrupt flag. Set by hardware, cleared by writing a 0.
SPI_SAFE 270C[3] 0 0 R/W
Limits SPI writes to SPI_CMD and a 16 byte region in
DRAM when set. No other write operations are permitted.
SPI_STAT 2708[7:0] 0 0 R
SPI_STAT contains the status results from the previous
SPI transaction.
Bit 7: Ready error: The 71M654x was not ready to read
or write as directed by the previous command.
Bit 6: Read data parity: This bit is the parity of all bytes
read from the 71M654x in the previous command. Does
not include the SPI_STAT byte.
Bit 5: Write data parity: This bit is the overall parity of the
bytes written to the 71M654x in the previous command.
It includes CMD and ADDR bytes.
Bit 4-2: Bottom 3 bits of the byte count. Does not include
ADDR and CMD bytes. One, two, and three byte
instructions return 111.
Bit 1: SPI FLASH mode: This bit is zero when the TEST
pin is zero.
Bit 0: SPI FLASH mode ready: Used in SPI FLASH
mode. Indicates that the flash is ready to receive
another write instruction.