Specifications
ST43401N/ND and ST43402ND Reference Manual, Rev. C 27
At this point, the Message In phase is entered with a Disconnect message
code. Following the disconnect, the bus is in the Bus Free phase in preparation
for the Arbitration and Reselection phases.
After Reselection, the process continues with the Message In and Data In
phases previously described. The Status phase occurs at the end of the
operation. It allows the target to send status information to the initiator.
Status codes are contained in bits 5 to 1 of the status byte. The various
codes are shown in Table 11. The process ends with the Message In
phase and a Command Complete message followed by the Bus Free
phase.
Bus
Free
Arbitration
Selection
with
Attention
Message
Out
(identify)
Command
(read)
Message
In
(disconnect)
Bus
Free
Arbitration
Reselection
Message
In
(identify)
Data
In
Message
In
(save
pointer)
Message
In
(disconnect)
Bus
Free
Arbitration
Reselection
Message
In
(identify)
Data
In
Status
Message
In
(command
complete)
Bus
Free
Figure 13. Sequence of a typical command