User guide

SC3500 User Guide Ver 1.3 March 8, 2005 Page 4 of 28
3. GENERAL DESCRIPTION
3.1 SCSI Interface
An intelligent SCSI controller from Qlogic, the FAS209, handles the SCSI interface
for the SC3500. The FAS209 is SCSI-I and SCSI II compliant, and automates much
of the interface overhead. It has a 16 byte FIFO, a DMA interface, and numerous
command and control registers.
The SC3500 employs the following attributes:
1. Single-ended drivers
2. Termination power derived from cable or drive
3. Selectable parity on the interface
4. "Hard" RESET implemented
5. Reservation queuing
The SC3500 has implemented all mandatory SCSI-I and SCSI- II commands and
several optional commands to enhance functionality. The following is a list of
commands and their equivalent hexadecimal representation.
1. Test Unit Ready 00h M
2. Rezero Unit 01h O
3. Request Sense 03h M
4. Format Unit 04h M
5. Read 08h M
6. Write 0Ah O
7. Inquiry 12h M
8. Mode Select 15h O
9. Reserve Unit 16h M
10. Release Unit 17h M
11. Mode Sense 1Ah O
12. Receive Diagnostics 1Ch O
13. Send Diagnostics 1Dh M
14. Read Capacity 25h M
15. Extended Read 28h M
16. Extended Write 2Ah O
17. Erase 2Ch O
18. Write & Verify 2Eh O
19. Verify 2Fh O
20. Read Defect 27h O
21. Write Buffer 3Bh O
22. Read Buffer 3Ch O
23. Change Definition 40h O