Avago Technologies LSI53C825AE - Manual (Page 172)

4-84 Registers
Register: 0x49 (0xC9)
SCSI Timer One (STIME1)
Read/Write
R Reserved 7
HTHBA Handshake-to-Handshake Timer Bus Activity
Enable
6
Setting this bit causes this timer to begin testing for SCSI
REQ/ and ACK/ activity as soon as SBSY/ is asserted,
regardless of the agents participating in the transfer.
GENSF General Purpose Timer Scale Factor 5
Setting this bit causes this timer to shift by a factor of 16.
See
Table 4.8 for Timeout Periods, 50 MHz clock.
7 6 5 4 3 0
R HTHBA GENSF HTHSF GEN[3:0]
x 0 0 0 0 0 0 0
Table 4.8 Timeout Periods, 50 MHz Clock
HTH[7:4], SEL[3:0],
GEN[3:0]
1
Minimum Timeout
(50 MHz Clock)
2
GENSF = 0 GENSF = 1
0000 Disabled Disabled
0001 100
µ
s 1.6 ms
0010 200
µ
s 3.2 ms
0011 400
µ
s 6.4 ms
0100 800
µ
s 12.8 ms
0101 1.6 ms 25.6 ms
0110 3.2 ms 51.2 ms
0111 6.4 ms 102.4 ms
1000 12.8 ms 204.8 ms
1001 25.6 ms 409.6 ms
1010 51.2 ms 819.2 ms
1011 102.4 ms 1.6 s
1100 204.8 ms 3.2 s