CXD1804AR Datasheet, PDF (81/103 Pages) Sony Corporation – CD-ROM Decoder

CXD1804AR
2-5-3. Stream and Bus-Free (C2h)
Description: The stream command is executed.
Preparation: A number of operations must be performed before issuing this command.
1) Specify the CXD1804AR operation with the SCCONF0 (60h), SCCONF1 (61h) and SCCONF2
(62h) registers.
2) Specify Disconnect allowed/not allowed and the operation when the ATN condition is
established with the SCSTCONF register.
3) Write the message to be transferred in the Message In phase immediately after Reselection,
and the data to be transferred in the status and Message In phases of the terminate I/O
sequence beforehand in the SCSTRSLM, SCSTTIOS and SCSTTIOM registers, respectively.
4) Prepare for auto transfer on the decoder block side.
Operation: When Disconnect is allowed, the following sequences are executed.
a) The following sequence is executed each time the buffer data reaches the buffer full ratio
during transfer.
Reselection → Message In → Data In → Message In → Disconnect
b) The following sequence is executed only during the final connection.
Reselection → Message In → Data In → Status → Message In → Bus-Free
When Disconnect is not allowed, the following sequence is executed.
a) Data In → Status → Message In → Bus-Free
Interrupt: FUNCCMPL Function complete (INTSTS2 register (72h), bit 7)
Microcode status:
The microcode status value when the command is completed has the following meanings.
Code
Description
00h Completed normally.
01h The CXD1804AR was selected and an error occurred in the Message In phase.
02h The CXD1804AR was selected and operation shifted to the command phase.
03h Reselection failed.
04h The ATN condition was established in the Message In phase immediately after Reselection.
05h The ATN condition was established in the Data In phase.
06h The ATN condition was established in the Message In phase during Disconnect.
07h The ATN condition was established in the Status phase during terminate I/O.
08h The ATN condition was established in the Message In phase during terminate I/O.
The meaning of each code after the stream pause command (C4h) has been issued is basically
the same. However, the meaning of the following codes changes slightly.
Code
Description
00h _{Completed normally. However, the stream is interrupted.}
The ATN condition was established in the Message In phase immediately after Reselection.
04h _{When the ATN condition is not established, the data to be transferred has already been}
transferred and the stream is interrupted.
The ATN condition was established in the Data In phase.
05h _{When the ATN condition is not established, the data to be transferred has already been}
transferred and the stream is interrupted.
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