Fujitsu MCP3064SS Time monitoring feature, Switching direction of transfer over the data bus

SCSI BUS

Data Release Delay + Bus Settle Delay (Min) Deskew Delay (Max)

Data Release Delay (Max)

Figure 7.18 Switching direction of transfer over the data bus

7.6.11 Time monitoring feature

The ODD has a time monitoring feature for the SCSI bus to prevent hang-up of the SCSI bus in the case that the TARG cannot receive a response from the INIT in the RESELECTION or INFORMATION TRANSFER phase.

(1) Time monitoring in RESELECTION phase

The ODD monitors the time of the response (BSY signal) from the INIT in the RESELECTION phase. When the INIT does not send the BSY signal within a specified period, the ODD executes the timeout process (see Subsection 7.6.4) to free the SCSI bus and then executes the retry process (see Section 6.1) of the RESELECTION phase in "MCD3130SS, MCE3130SS, MCK3130SS, MCM3064SS, MCM3130SS Optical Disk Drives SCSI Logical Interface Specifications."

(2) Time monitoring in INFORMATION TRANSFER phase

The ODD monitors the timing of the ACK signal against the REQ signal in the INFORMATION TRANSFER phase. Time monitoring is executed during the following period:

•COMMAND, STATUS, or MESSAGE phase:

Time taken from the moment of sending the REQ signal of the first byte to the moment of completing the reception of the ACK signal of the last byte of the phase.

7-38 C156-E228-02EN