Sierra M6
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2 SAS/SATA Protocol Analyzer User Manual
331
Scenario Properties
LeCroy Corporation
SATA Scenario Properties have a Smart Hold option, which is on by default.
Each port monitors incoming data, which originated with the other device’s receiver, as
close as possible to where it enters the bus engine. If a port detects a HOLD primitive
during a SATA frame, the port stops reading data from the FIFO and generates HOLDA. The
HOLD propagates through the bus engine and eventually goes to the other device, where
the HOLD causes the other device to send HOLDA. (The bus engine FIFOs must be deep
enough to hold all the traffic that the other device sends while the HOLD propagates. The
port drops all incoming HOLDA conditions, so HOLDAs are never put in the FIFOs or made
visible to the sequencers.)
After this, the port that had been receiving the HOLD stops sending HOLDA and attempts
to read data from the FIFO. The termination of HOLD propagates through the bus engine
and then causes the other device to restart transmission, which puts data into the FIFO.
Note:
If both sides send HOLD primitives that overlap, the receivers drop the HOLD conditions to avoid
overflowing the FIFOs.
If you turn off the Smart Hold option, the port does not send HOLDA when it detects a
HOLD primitivew during a SATA frame.