Sun Microsystems 220R - Manual (Page 269)

C.1.11.1 Host Adapter
The host adapter is a Symbios Logic PCI-SCSI I/O processor IC. The host adapter
and all target devices comply with the Fast-20 single-ended drivers and receivers
characteristics. The electrical characteristics of the output buffers include:
4 Vol (output low) equals 0 to 0.5 VDC with Iol at 48 mA (signal asserted)
4 Voh (out high) equals 2.5 to 3.7 VDC (signal negated)
4 trise (rising slew rate) equals 520 mV per nanosecond maximum (0.7 to 2.3 VDC)
4 tfall (falling slew rate) equals 520 mV per nanosecond maximum(2.3 to 0.7 VDC)
The Fast-20 electrical characteristics for the host adapter and target device include:
4 Vil (input low) equals 1.0 VDC maximum (signal true)
4 Vih (input high) equals 1.9 VDC minimum (signal false)
4 Iil (input low current) equals +/- 20 m A at Vi equals 0.5 VDC
4 Iih (input high current) equals +/- 20 m A at Vi equals 2.7 VDC
4 Minimum input hysteresis equals 0.3 VDC
C.1.11.2 Supported Target Devices
The SCSI subsystem supports a maximum of four internal devices, including the host
adapter. The CD-ROM drive is a narrow device. A unipack with one drive or a
six-pack, accommodating six drives, can be used as external devices.
Functional Description 269