Quantum 10K II - Manual (Page 326)

Appendix B. SCSI Bus Signal Timing
Quantum Atlas 10K II Ultra 160/m SCSI Hard Disk Drives B–5
Table B–3 Single Transition (ST) SCSI Bus Data and Information Phase Timing
Values (Note 4)
Description Asynch Fast-5 Fast-10 Fast-20 Fast-40
ATN Transmit Setup Time 90 ns 33 ns 33 ns 21.5 ns 19.25ns
ATN Receive Setup Time 45 ns 17 ns 17 ns 8.5 ns 6.75 ns
Cable Skew (note 1) 4 ns 4 ns 4 ns 3 ns 2.5 ns
Receive Assertion Period (note 2) N/A 70 ns 22 ns 11 ns 6.5 ns
Receive Hold Time (note 2 and note 3) N/A 25 ns 25 ns 11.5 ns 4.75 ns
Receive Negation Period (note 2) N/A 70 ns 22 ns 11 ns 6.5 ns
Receive Setup Time (note 2 and note 3) N/A 15 ns 15 ns 6.5 ns 4.75 ns
Receive REQ (ACK) Period Tolerance N/A 1.1 ns 1.1 ns 1.1 ns 1.1 ns
Signal Timing Skew 8 ns 8 ns 8 ns 5 ns 4.5 ns
REQ (ACK) Period N/A 200 ns 100 ns 50 ns 25 ns
Transmit Assertion Period (note 2) N/A 80 ns 30 ns 15 ns 8 ns
Transmit Hold Time (note 2 and note 3) N/A 53 ns 33 ns 16.5 ns 9.25 ns
Transmit Negation Period (note 2) N/A 80 ns 30 ns 15 ns 8 ns
Transmit Setup Time (note 2 and note 3) N/A 23 ns 23 ns 11.5 ns 9.25 ns
Transmit REQ (ACK) Period Tolerance N/A 1 ns 1 ns 1 ns 1 ns
Notes: 1 Cable Skew is measured at each device connection with the transmitted skew subtracted from
the received skew.
2 See SPI-3 specifications for measurement points.
3 See SPI-3 specifications for examples of how to calculate setup and hold timing.
4 SCSI bus timing values specified by the maximum transfer rate for the given range shall apply
even if a slower transfer rate within the given range is negotiated.