Fujitsu MBA3073 SERIES Technical Manual page 181

d. Transfer mode setup from HDD to INIT
When the synchronous data transfer mode is allowed by the CHANGE DEFINITION
command, the HDD shall execute one of the following operations if the INIT still continue the
default transfer mode.
(a) When the ATTENTION condition has been generated:
If an ATTENTION condition exists before the COMMAND phase and if the INIT does not
send the SYNCHRONOUS DATA TRANSFER REQUEST message after the end of
COMMAND phase, the HDD shall try to select the synchronous data transfer mode by
sending the SYNCHRONOUS DATA TRANSFER REQUEST message to the INIT.
Table 2.6 shows the contents of the SYNCHRONOUS DATA TRANSFER REQUEST
message sent from the HDD and the data transfer mode set to the HDD and INIT by the
response of this message from the INIT. If the INIT does not respond as defined on Table
2.6, the HDD assumes that the synchronous data transfer is unavailable and selects the
asynchronous data transfer mode between the HDD and the INIT.
If an ATTENTION condition has occurred in the COMMAND phase and if the HDD has
entered the BUS FREE phase or STATUS phase as the result of MESSAGE OUT phase
operations, the default transfer mode of the INIT continues when the HDD cannot send
the SYNCHRONOUS DATA TRANSFER REQUEST message.
(b) When the ATTENTION condition has not been generated:
If the ATTENTION condition does not exist, the HDD does not send the SYNCHRONOUS
DATA TRANSFER REQUEST message to the INIT. In this case, data is transferred in the
asynchronous transfer mode. The default transfer mode of the INIT is released.
174 C141-C015