Command Phase; Data Phase; Figure 1.38 Data Sequence At Data Transfer - Fujitsu MBA3073 SERIES Technical Manual

Number of information
items transferred
1.6.6

COMMAND phase

The COMMAND phase is a bus phase in which the TARG requests the INIT to transfer command
information (CDB) to the TARG. The TARG keeps the C/D signal true and the I/O and MSG
signals false during REQ/ACK handshaking in this phase.
1.6.7

DATA phase

The DATA phase is divided into DATA IN and DATA OUT phases according to the direction of
data transfer. In a DATA phase, synchronous data transfer can be performed.
(1) DT DATA IN phase
The DT DATA IN phase allows the target to request that data be sent to the initiator from the
target using DT data transfers. The target shall assert the I/O and MSG signals and negate the C/D
signal during the REQ/ACK handshake(s) of this phase.
(2) DT DATA OUT phase
The DT DATA OUT phase allows the target to request that data be sent from the initiator to the
target using DT data transfers. The target shall assert the MSG signal and negate the C/D and I/O
signals during the REQ/ACK handshake(s) of this phase.
(3) ST DATA IN phase
The ST DATA IN phase allows the target to request that data be sent to the initiator from the
target using ST data transfers. The target shall assert the I/O signal and negate the C/D and MSG
signals during the REQ/ACK handshake(s) of this phase.
(4) ST DATA OUT phase
The ST DATA OUT phase allows the target to request that data be sent from the initiator to the
target using ST data transfers. The target shall negate the C/D, I/O, and MSG signals during the
REQ/ACK handshake(s) of this phase.
26
1 Unused
2 Unused
DB15.................DB8 DB7..................DB0
1 B

Figure 1.38 Data sequence at data transfer

P cable
A "8-bit mode"
B
A "16-bit mode"
C141-C015