Status Phase; Message Phase; Figure 1.39 Data Transfer Rate In Synchronous Mode - Fujitsu MBA3073 SERIES Technical Manual

(4) Ultra-160M fast synchronous data transfer mode only for LVD (Fast-80 SCSI). This code is
only valid if the PROTOCOL OPTIONS field has a value selected that supports double-
transition data transfers.
(5) Ultra-320 fast synchronous data transfer mode only for LVD (Fast-80 SCSI). This code is only
valid if the PROTOCOL OPTIONS field has a value selected that supports double-transition
and information units transfer.
(6) PPR : PARALLEL PROTOCOL REQUEST
(7) SDTR : SYNCHRONOUS DATA TRANSFER REQUEST

Figure 1.39 Data transfer rate in synchronous mode

1.6.8

STATUS phase

In a STATUS phase, the TARG requests to transfer status information from the TARG to the
INIT. The TARG keeps the C/D and I/O signals true and the MSG signal false during REQ/ACK
handshaking in this phase.
1.6.9

MESSAGE phase

The MESSAGE phase is divided into MESSAGE IN and MESSAGE OUT phases depending on
the direction of message information transfer. In either phase, several messages can be transferred.
The first byte transferred in a MESSAGE phase must be a single-byte message or the first byte of
a multiple-byte message. If the message consists of more than one byte, all bytes must be
transferred in a single MESSAGE phase. For details of message types and their operation, refer to
Chapter 2.
(1) MESSAGE IN phase
In a MESSAGE IN phase, the TARG requests to transfer message information from the TARG to
the INIT. The TARG keeps the C/D, I/O, and MSG signals true during REQ/ACK handshaking
in this phase.
28 C141-C015