Datasheet

DS1878
SFP+ Controller with Digital LDD Interface
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Table 02h, Register BAh: ISTEPH
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)
BAh 2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
BIT 7 BIT 0
ISTEP is the initial step value used at power-on or after a TXD pulse to control the BIAS register. The particular
ISTEP used depends on the value of TINDEX and ISTEPTI (Table 02h, Register C5h). When TINDEX > ISTEPTI,
ISTEPH is used. When TINDEX < ISTEPTI, ISTEPL is used. 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)
BBh 2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
BIT 7 BIT 0
See the ISTEPH register description.
Table 02h, Register BBh: ISTEPL