Seagate Ultra160 Product Manual page 247

SCSI Interface Product Manual, Rev. B
The margin control fields contain two's complement values as shown in the table below.
Value
Binary Decimal
0111b 7
0110b 6
0101b 5
0100b 4
0011b 3
0010b 2
0001b 1
000b 0
111b -1
1110b -2
1101b -3
1100b -4
1011b -5
1010b -6
1001b -7
1000b -8
Table 161: Margin control subpage
Bit 7
Byte
0
1
2
3
4
5
6
7
8
.
.
15
[1] The DRIVER STRENGTH field indicates the relative amount of driver source current used by the driver
(see Section 7.3.2 in the ANSI SPI-4 specification). The DRIVER STRENGTH field affect both the strong
and weak drivers. A larger value indicates more driver source current.
[2] The DRIVER ASYMMETRY field indicates the relative difference between the amplitudes of asserted and
negated signals launched from the driver. A larger value indicates a relatively stronger asserted signal
compared to the negated signal.
[3] The DRIVER PRECOMPENSATION field indicates the relative difference between the weak driver and
the strong driver amplitudes when precompensation is enabled. A larger value indicates a larger differ-
ence between the weak and strong amplitudes.
Parameter values
Maximum setting
Recommended default value
Minimum setting
6 5
DRIVER STRENGTH [1]
DRIVER ASYMMETRY [2]
DRIVER SLEW RATE [4]
4 3
Reserved
DRIVER PRECOMPENSATION [3]
Reserved
Reserved
Reserved
Vendor-specific
Reserved
2 1
Reserved
Reserved
229
0