If the I/O signal is true (transfer to the initiator), the target shall first drive the DB(7-0,P) signals to their desired values, wait at least one deskew delay plus one cable skew delay, then assert the REQ signals. The DB(7-0,P) signals shall be held valid for a minimum of one deskew delay plus one cable skew delay plus one hold time after the assertion of the REQ signal. The target shall assert the REQ signal for a minimum of an assertion period. The target may then negate the REQ signals within one hold time of the transition of the REQ signal to true. The initiator shall then respond with an ACK pulse.

If the I/O signal is false (transfer to the target), the initiator shall tranfer one byte for each REQ pulse received. After receiving the leading edge of a REQ pulse, the initiator shall first drive the DB(7- 0,P) signals to their desired values, delay at least one deskew delay plus one cable skew delay, then assert the ACK signal. The initiator shall hold the DB(7-0,P) signals valid for at least one deskew delay plus one cable skew delay plus one hold time after the assertion of the ACK signal. The initiator shall assert the ACK signal for a minimum of an assertion period. The initiator may then negate the ACK signal and may one hold time of the transition of the ACK signal to true.

COMMAND Phase

The COMMAND phase allows the target to request command information from the initiator.

The target shall assert the C/D signal and negate the I/O and MSG signals during the REQ/ACK handshake(s) of this phase.

Data Phase

The data phase is a term that encompasses both the DATA IN phase and the DATA OUT phase.

3-22

M3099GX/GH OEM Manual