Datasheet
44 Maxim Integrated
SFP Controller for Dual Rx Interface
DS1877
Table 02h, Register 81h: TEMPERATURE INDEX (TINDEX)
Table 02h, Register 82h–85h: RESERVED
Table 02h, Register 86h: DEVICE ID
FACTORY DEFAULT 00h
READ ACCESS PW2 or (PW1 and RWTBL2) or (PW1 and RTBL2)
WRITE ACCESS (PW2 and AEN = 0) or (PW1 and RWTBL2 and AEN = 0)
A2h AND B2h MEMORY Common A2h and B2h memory locations
MEMORY TYPE Volatile
81h 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT 7 BIT 0
Holds the calculated index based on the temperature measurement. This index is used for the address during lookup
of Table 04h. Temperature measurements below -40NC or above +102NC are clamped to 80h and C7h, respectively.
The calculation of TINDEX is as follows:
Temp_Value 40 C
TINDEX 80h
2C
+°
= +
°
For the temperature-indexed LUTs (2NC), the index used during the lookup function for each table is as follows:
Table 04h (DAC) 1 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
TINDEX
0
For the 8-position LUT tables, the following table shows the lookup function:
TINDEX 1000_0xxx 1001_0xxx 1001_1xxx 1010_0xxx 1010_1xxx 1011_0xxx 1011_1xxx 11xx_xxxx
BYTE F8 F9 FA FB FC FD FE FF
TEMP (NC)
< -8 -8 to +8 +8 to +24 +24 to +40 +40 to +56 +56 to +72 +72 to +88
R +88
FACTORY DEFAULT 00h
READ ACCESS N/A
WRITE ACCESS N/A
A2h AND B2h MEMORY N/A
MEMORY TYPE N/A
These registers are reserved.
FACTORY DEFAULT 77h
READ ACCESS PW2 or (PW1 and RWTBL2) or (PW1 and RTBL2)
WRITE ACCESS N/A
MEMORY TYPE ROM
86h 0 1 1 1 0 1 1 1
BIT 7 BIT 0
Hardwired connections to show the device ID.