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Chapter 14
Queued CSI (CSI30, CSI31)
User’s Manual U16702EE3V2UD00
14.3.9 Description of the Operation Modes
(1)
Transmit Only Mode
Setting the CSIM register's CTXE =1 and CRXE = 0 places the Queued CSI in transmit only mode.
A transmission starts when transmit data is written in the SFDB register. The current condition of
the SIRB buffer and SIO register no effect. The data in the SIRB and the SIO buffer is undefined
after completion of the transmission.
(2)
Receive Only Mode
Setting the CSIM register's CTXE = 0 and CRXE = 1 places the Queued CSI in receive only mode.
A reception starts when dummy data is written in the SFDB register. It is mandatory, though, that
the SIRB and SIO are empty. If a receive operation is terminated while the previous receive data
remains unread in SIRB, the Queued CSI is placed on wait status until the previous data is com-
pletely read and SIRB becomes empty.
(3)
Transmit/Receive Mode
Setting the CSIM register's CTXE = 1 and CRXE = 1 places the Queued CSI in transmit/receive
mode. A transfer (meaning transmission and reception) starts when transmit data is written in the
SFDB register. Note that an empty SIRB or SIO is mandatory. If a receive operation is terminated
while the previous receive data remains unread in SIRB, the Queued CSI is placed on wait status
until the previous data is completely read and SIRB becomes empty.
In FIFO buffer transfer mode with slave mode, only the first dummy data write operation is
required. There is no need to write chip-select data, as these bits are ignored.
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