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SPI-4.2 Lite v4.3 User Guide www.xilinx.com 97
UG181 June 27, 2008
Source Core
R
♦ Action: The Source core will transmit idle cycles when Reset_n is asserted.
When Reset_n is deasserted, the core will initiate the synchronization start-up
sequence.
• Case 2: If the core receives a number of consecutive DIP-2 errors as defined by
NumDip2Errors.
♦ Action: The Source core terminates the current packet at the next burst boundary,
and begins transmitting training patterns on TDat[15:0].
• Case 3: If the core receives four framing sequences "11" in a row on TStat.
♦ Action: The Source core terminates the current packet at the next burst boundary,
and begins transmitting training patterns on TDat[15:0].
After the Source core is in frame, it will resume transmitting the remaining data stored in
the FIFO. (Note that if SrcFifoReset_n is asserted, the Source core will remain in frame
(SrcOof will be deasserted).
Source DIP-2 Error Handling
The Source core asserts the DIP-2 error flag (SrcDIP2Err) when a DIP-2 error is received
on TStat.
Source Status Frame Word Handling
The Source core asserts the frame error flag (SrcStartFrameErr) when an incorrect
frame word (non-”11”) is received on TStat at the end of the status sequence.
Source Pattern Error Handling
Source Pattern Error (SrcPatternErr) is asserted when an illegal data pattern is written
into the Source FIFO. The two conditions that will trigger this error signal are:
• Case 1: The address was changed on a non-credit boundary, without an EOP: In this
case, the remainder of that packet will be terminated with an EOP Abort, and sent out
the SPI-4.2 bus.
• Case 2: The SrcFFMod signal is non-zero without an EOP: In this case, an EOP abort
will not be asserted. When this occurs, the Source core will ignore the SrcFFMod
value and send the data word with MOD set to zero.
Incorrect Burst Termination
When a burst (that has an odd number of bytes), terminated with an EOP, is not padded
with zeros, the Source core sets unused bytes to zero (as required by the SPI4 specification).
The Source core will also assert SrcPatternErr, but the core will not assert an EOP abort.