Fujitsu MBA3073 SERIES Technical Manual page 82

b. Transfer from INIT to TARG
When the I/O signal is false, the information of the data bus is transferred from the INIT to the
TARG. The following explains the information transfer sequence.
1) The TARG asserts the REQ signal to request the INIT for information transfer.
2) The INIT asserts the ACK signal at least one System Deskew Delay + Cable Skew Delay
after sending valid information of the requested type on the data bus. The information on
the data bus must be maintained until the REQ signal becomes false on the INIT.
3) The TARG fetches data from the data bus after the ACK signal becomes true, and
negates the REQ signal to report the completion of reception.
4) When the REQ signal becomes false on the INIT, the INIT negates the ACK signal.
After that, the INIT may release or change the DB(7-0, P_CRCA) or DB(15-0, P_CRCA,
P1) signals.
5) After the ACK signal becomes false, the TARG proceeds to the next byte transfer stage.
2 C141-C015