Avago Technologies LSI53C876E - Manual (Page 177)

SCSI Registers 4-83
R Reserved 5
GPIO[4:2] GPIO Enable [4:2]
General purpose control, corresponding to bit 4 in the
General Purpose (GPREG) register and the GPIO4 pin.
GPIO4 powers-up as a general purpose output, and
GPIO[3:2] power-up as general purpose inputs.
GPIO[1:0] GPIO Enable [1:0]
These bits power-up set, causing the GPIO1 and GPIO0
pins to become inputs. Clearing these bits causes
GPIO[1:0] to become outputs.
Register: 0x48
SCSI Timer Zero (STIME0)
Read/Write
HTH Handshake-to-Handshake Timer Period [7:4]
These bits select the handshake-to-handshake time-out
period, the maximum time between SCSI handshakes
(SREQ/ to SREQ/ in target mode, or SACK/ to SACK/ in
initiator mode). When this timing is exceeded, an interrupt
is generated and the HTH bit in the
SCSI Interrupt Status
One (SIST1) register is set. The following table contains
time-out periods for the Handshake-to-Handshake Timer,
the Selection/Reselection Timer (bits [3:0]), and the
General Purpose Timer (
SCSI Timer One (STIME1) ,
bits [3:0]). For a more detailed explanation of interrupts,
refer to
Chapter 2, “Functional Description.”
7 4 3 0
HTH[3:0] SEL[3:0]
0 0 0 0 0 0 0 0