CIRCC Datasheet, PDF (63/70 Pages) SMSC Corporation – Consumer Infrared Communications Controller

String Move
DMASEtrninagblMe _ove
TxDEMnAabElneable
RxIOEWnable
TxServReq _IOR
FIFO Int.RExnSaebrlveReq
FIFFOIFOIntIenrtr. uEpntable
DFaIFtaODInotneerrupt
EOMEOInMterInruteprtrupt
FIFGIGURUERE3132- I-NITNETRERRURPUTPTDRDIRVIEVNENPRPOROGGRARMAMMMEDEDI/OI/OTRRAENCSEMIVIET TTIIMMIINNGG
Receive
Receiving messages with Programmed I/O using
FIFO Interrupt requires reading a fixed number of
data bytes, usually related to the threshold,
whenever the FIFO Interrupt becomes active.
An appropriate FIFO Threshold value allows the
host to efficiently satsify the FIFO service
requests until the message reception is
complete.
IOCHRDY Time-out
In programmed I/O mode when AEN = low and
String Move = active, IOCHRDY can be used to
slightly extend the access cycle if the FIFO is
temporarily unable to fulfill the transfer request
(Figure 33). If IOCHRDY remains inactive for
more than 10Fs, a time-out error occurs and
subsequent IOCHRDY cycles are prevented until
the string move bit is specifically reactivated.
Because of the 10Fs IOCHRDY time-out, it is
recommended that string move timing only be
used for 1.152 Mbps transfers and above.
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