Owner's manual

DS1874
SFP+ Controller with Digital LDD Interface
68 ______________________________________________________________________________________
Table 02h, Register BAh: RESERVED
FACTORY DEFAULT 00h
READ ACCESS PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS PW2 or (PW1 and RWTBL246)
MEMORY TYPE Nonvolatile (SEE)
This register is reserved.
FACTORY DEFAULT 00h
READ ACCESS PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS PW2 or (PW1 and RWTBL246)
MEMORY TYPE Nonvolatile (SEE)
BBh 2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
BIT 7 BIT 0
The initial step value used at power-on or after a TXD pulse to control the BIAS register. At startup, this value plus
2
0
= 1 is continuously added to the BIAS register value until the APC feedback (MON2) is greater than its threshold.
At that time, a binary search is used to complete the startup of the APC closed loop. If the resulting math operation is
greater than IBIASMAX (Table 02h, Register EEh), the result is not loaded into the BIAS register, but the binary
search is begun to complete the initial search for APC. During startup, the BIAS register steps causing a higher bias
value than IBIASMAX do not create the BIAS MAX alarm. The BIAS MAX alarm detection is enabled at the end of the
binary search.
FACTORY DEFAULT 00h
READ ACCESS PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS PW2 or (PW1 and RWTBL246)
MEMORY TYPE Nonvolatile (SEE)
BCh 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT 7 BIT 0
Fast-comparison DAC threshold adjust for high TXP. This value is added to the APC DAC value recalled from
Table 04h. If the sum is greater than 0xFF, 0xFF is used. Comparisons greater than V
HTXP
, compared against
V
MON2
, create a TXP HI alarm. The same ranging applied to the APC DAC should be used here.
V
HTXP
=
Full Scale
255
 HTXP + APC DAC
()
Table 02h, Register BBh: ISTEP
Table 02h, Register BCh: HTXP