Scsi; Host Adapter - Sun Microsystems Sun Blade 1000 Service Manual

C.1.17

SCSI

The workstation implements a small computer system interface (SCSI) for UltraSCSI,
40 Mbps parallel interface bus. UltraSCSI provides the following:
Efficient peer-to-peer I/O bus devices
Mechanical, electrical, and timing specification definition that support transfer
rates of 20 or 40 Mbytes/sec. (corresponding to the data path width of an 8-bit, or
16-bit bus, respectively)
Peak bandwidth of 40 Mbytes/sec. (with implemented 16-bit bus width)
The internal SCSI bus is terminated at each end. One set of terminators is located
close to the DVD-ROM drive connector on the DVD-ROM SCSI cable. A second set
of terminators is located close to the internal SCSI connector. The following figure
shows the SCSI bus configuration.
FIGURE C-14
C.1.17.1

Host Adapter

The host adapter is a QLogic PCI-SCSI ASIC. The host adapter and all target devices
comply with the UltraSCSI single-ended drivers and receivers characteristics. The
electrical characteristics of the output buffers include:
V
ol
V
oh
t
rise
t
fall
DVD-ROM
drive
(8-bit)
SCSI bus A
T
Internal SCSI bus
Configuration for the SCSI Bus
(output low) equals 0 to 0.5 VDC with I
(out high) equals 2.5 to 3.7 VDC (signal negated)
(rising slew rate) equals 520 mV per nanosecond maximum (0.7 to 2.3 VDC)
(falling slew rate) equals 520 mV per nanosecond maximum (2.3 to 0.7 VDC)
SCSI
controller
(UltraSCSI)
T
T
SCSI bus B
at 48 mA (signal asserted)
ol
Appendix C Functional Description
External to chassis
connector J2202
C-41