User guide
DS1875
PON Triplexer and SFP Controller
62 ______________________________________________________________________________________
Table 02h, Register 81h: Temperature Index (TINDEX)
FACTORY DEFAULT 00h
READ ACCESS PW2
WRITE ACCESS PW2 and AEN = 0
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 Tables 04h, 05h, 07h, and 08h. Temperature measurements below -40°C or above +102°C are clamped
to 00h and C7h, respectively. The calculation of TINDEX is as follows:
TINDEX =
Temp _ Value + 40°C
2°C
+ 80h
For the temperature-indexed LUTs, the index used during the lookup function for each table is as follows:
Table 04h (MOD) 1 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
TINDEX
0
Table 05h (APC) 1 0 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
Table 07h (PWM)
1 0 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
Table 08h (BIAS) 1 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
TINDEX
0
Table 02h, Register 82h: MOD DAC
FACTORY DEFAULT 00h
READ ACCESS PW2
WRITE ACCESS PW2 and MOD EN = 0
MEMORY TYPE Volatile
82h 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT 7 BIT 0
The digital value used for MOD and recalled from Table 04h at the adjusted memory address found in TINDEX.
This register is updated at the end of the temperature conversion.
V
MOD
=
Full Scale
255
MOD DAC