CXD1185CQ/CR
<Command phase execution>
Switching to the command phase
Wait until the target device switches the SCSI bus to the command phase (PHC bit set to “1”).
9
10 Command send
Set the number of command bytes in the transfer byte counter. Write “Transfer Information” command
into the command register. (this time set the TRBE bit to “1” and DMA bit to “0”). Write the command
bytes into the SCSI data register. After confirming that the CIP bit is set to “0”, read interrupt request
registers 1 and 2.
<Data-in phase execution>
11 Switching to the data-in phase
Wait until the target device switches the SCSI bus to the data-in phase (PHC bit set to “1”).
12 Data receive
Set the number of data bytes received in the transfer byte counter. Write “Transfer Information”
command into the command register (with both DMA bit and TRBE bit set to “1”).
Note that programming of DMA controller is also required starting DMA transfer. After confirming that the
CIP bit is set to “0”, read interrupt request registers 1 and 2.
<Status phase execution>
13 Switching to the status phase
Wait until the target devices switches the SCSI bus to the status phase (PHC bit set to “1”).
14 Status receive
Write “Transfer Information” command in the command register (both DMA bit and TRBE bit are “0”).
After confirming that the CIP bit is set to “0”, read interrupt request registers 1 and 2.
The status byte is read from the data register.
<Message-in phase execution>
15 Switching to the message-in phase
Wait until the target device switches the SCSI bus to the message-in phase (PHC bit set to “1”).
16 Message receive
Write “Transfer Information” command in the command register (both DMA bit and TRBE bit are “0”).
After confirming that the CIP bit is set to “0”, read interrupt request registers 1 and 2. The message byte
is read from the data register.
17 Halting ACK signal drive
Write “Deassert ACK” command in the command register to inactivate ACK signal. After confirming that
the CIP bit is “0”, read the interrupt request registers 1 and 2.
<Disconnect>
18 Wait until the DCNT bit is set to “1”.
All SCSI phases are covered in 1-17 above.
If a disconnect message is sent from the target device when in the data phase, the status phase is
skipped and processing continues with the message in phase. When reselection is performed from the
target device (RSL bit set to “1”), it is necessary to wait until the FNC bit is set to “1”. Then read the
monitor SCSI control register and perform the processing appropriate for the current SCSI phase.
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SONY [ SONY CORPORATION ]
