Spi "Bit Bang" Mode - VersaLogic EBX-22 Reference Manual

SPI "B B " M
IT ANG
A special register is available at 1D7h, which enables the direct control ("bit banging") of the SPI
interface. To use this register, the SPI field (bits D6-D5) of the MODCON register (1DFh) must
be set to 0h (see Table 44 for mode control settings).
SPIBB (Read/Write) 1D7h
D7
SPI_IN SPI_INT
Bit Mnemonic
D7 SPI_IN
D6 SPI_INT
D5 SPI_CLK
D4 SPI_OUT
D3-D0 SPI_CS
EBX-22 Reference Manual
ODE
D6 D5 D4
SPI_CLK SPI_OUT
Table 33: SPIBB Bit Assignments
Description
SPI Input – This bit is read-only.
SPI Interrupt – This bit is read-only.
SPI Clock – This bit is read/write.
SPI Output – This bit is read/write.
SPI Chip Select – These bits are read/write.
Interfaces and Connectors
D3 D2 D1
SPI_CS3 SPI_CS2 SPI_CS1
D0
SPI_CS0
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