Product manual
Barracuda 2LP Product Manual, Rev. D 85
Table 20. Disc drive SCSI timing
Waveform Waveform
Description symbol [1] table [1] Typical Max
Target select time (no arbitration) T00 N/A < 1 µs < 250 µs
Target select time (with arbitration) T01 4.5-1,2 2.31 µs 2.36 µs
Target select to command T02 4.5-1 3.33 µs 3.34 µs
Target select to MSG out T03 4.5-2 1.51 µs 1.54 µs
Identify MSG to command T04 4.5-3 3.34 µs 3.36 µs
Command to status T05 4.5-5 Command dependent
Command to data (para. in) T06 4.5-9 Command dependent
Command to data (para. out) T07 4.5-10 Command dependent
Command to data (write to data buffer) T08 4.5-10 Command dependent
Command to disconnect MSG T09 4.5-6 Command dependent
Disconnect MSG to bus free T10 4.5-6,14 0.64 µs 0.68 µs
Disconnect to arbitration (for re-select) T11 4.5-6 Command dependent
This measures disconnected CMD overhead
Target win arbitration (for re-select) T12 4.5-7 2.8 µs
Arbitration to re-select T13 4.5-7 1.8 µs
Re-select to Identify MSG in T14 4.5-7 1.34 µs
Re-select Identify MSG to status T15 4.5-8 Command dependent
Re-select Identify MSG to data (media) T16 4.5-11 Command dependent
Data to status T17 4.5-15 Command dependent
Status to command complete MSG T18 4.5-5,8,15 1.0 µs
Command complete MSG to bus free T19 4.5-5,8,15 0.75 µs
Data to save data pointer MSG T20 4.5-14 4.5 µs
Save data pointer MSG to disconnect MSG T21 4.5-14 0.75 µs
Command byte transfer T22 4.5-4 0.04
Next command byte access 4.5-4
Next CDB byte access (byte 2 of 6) T23.6.2 4.5-4 0.55 µs 0.56 µs
Next CDB byte access (byte 3 of 6) T23.6.3 4.5-4 0.10 µs 0.10 µs
Next CDB byte access (byte 4 of 6) T23.6.4 4.5-4 0.09 µs 0.10 µs
Next CDB byte access (byte 5 of 6) T23.6.5 4.5-4 0.13 µs 0.14 µs
Next CDB byte access (byte 6 of 6) T23.6.6 4.5-4 0.13 µs 0.14 µs
Next CDB byte access (byte 2 of 10) T23.10.2 4.5-4 0.59 µs 0.60 µs
Next CDB byte access (byte 3 of 10) T23.10.3 4.5-4 0.14 µs 0.14 µs
Next CDB byte access (byte 4 of 10) T23.10.4 4.5-4 0.13 µs 0.14 µs
Next CDB byte access (byte 5 of 10) T23.10.5 4.5-4 0.12 µs 0.12 µs
Next CDB byte access (byte 6 of 10) T23.10.6 4.5-4 0.11 µs 0.12 µs
Next CDB byte access (byte 7 of 10) T23.10.7 4.5-4 0.10 µs 0.10 µs
Next CDB byte access (byte 8 of 10) T23.10.8 4.5-4 0.09 µs 0.10 µs
Next CDB byte access (byte 9 of 10) T23.10.9 4.5-4 0.13 µs 0.14 µs
Next CDB byte access (byte 10 of 10) T23.10.10 4.5-4 0.12 µs 0.12 µs