User's Manual

Table Of Contents
TiWi-SL MODULE
DATASHEET
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330-0085-R0.4 Copyright © 2011 LS Research, LLC Page 17 of 36
Port Name Input/Output Description
SPI_CLK Input Clock (0 MHz to 38.4MHz) from host to device
SPI_DI Input Data from host to device
SPI_CS Input CS signal from host to device
SPI_IRQ Output Interrupt from device to host
SPI_DO Output Data from device to host
Table 11: SPI Interface Signals Description
/CS and Bus Sharing Operation
The /CS line selects a specific device on the shared SPI bus. /CS is asserted at the beginning of an
SPI transaction and de-asserted when the transaction completes; /CS must not be de-asserted during
the transaction.
Bus sharing by multiple devices is implemented by asserting one /CS signal at a time and performing
transactions with a specific device. Device multiplexing is performed on a transaction basis rather than
on a byte or word basis.
SPI Transactions
NOTE
The first command to be sent to the device requires special consideration.
Write/Read Transactions
16-Bit Alignment
All data sent or received over the SPI interface are 16-bit aligned.
Write Operation: Host to device Data Transfer
Figure 5: SPI Write Transaction