Avago Technologies LSI53C825AE - Manual (Page 171)

Operating Registers 4-83
SEL[3:0] Selection Time-Out [3:0]
These bits select the SCSI selection/reselection time-out
period. When this timing (plus the 200
µ
s selection abort
time) is exceeded, the STO bit in the SCSI Interrupt
Status One (SIST1) register is set. For a more detailed
explanation of interrupts, refer to Chapter 2, “Functional
Description.”
Table 4.7 Timeout Periods
HTH[7:4],
SEL[3:0],
GEN[3:0]
1
Minimum Timeout
(40 or 160 MHz)
Minimum Timeout
(50 MHz)
0000 Disabled Disabled
0001 125
µ
s 100
µ
s
0010 250
µ
s 200
µ
s
0011 500
µ
s 400
µ
s
0100 1 ms 800
µ
s
0101 2 ms 1.6 ms
0110 4 ms 3.2 ms
0111 8 ms 6.4 ms
1000 16 ms 12.8 ms
1001 32 ms 25.6 ms
1010 64 ms 51.2 ms
1011 128 ms 102.4 ms
1100 256 ms 204.8 ms
1101 512 ms 409.6 ms
1110 1.024 s 819.2 ms
1111 2.048 s 1.6384 s
1. These values are correct if the CCF bits in the SCSI Control
Three (SCNTL3) register are set according to the valid
combinations in the bit description.