Ds1874 sfp+ controller with digital ldd interface – Rainbow Electronics DS1874 User Manual
Page 56
DS1874
SFP+ Controller with Digital LDD Interface
56
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Table 02h, Register 81h: Temperature Index (TINDEX)
FACTORY
DEFAULT
00h
READ ACCESS
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS
(PW2 and AEN = 0) or (PW1 and RWTBL246 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, 06h–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 06h (APC)
1
0
TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
Table 07h (DAC1)
1 0 TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
Table 08h (DAC2)
1
0
TINDEX
6
TINDEX
5
TINDEX
4
TINDEX
3
TINDEX
2
TINDEX
1
FACTORY
DEFAULT
0000h
READ ACCESS
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS
(PW2 and MOD EN = 0) or (PW1 and RWTBL246 and MOD EN = 0)
MEMORY
TYPE Volatile
82h
0 0 0 0 0
0 0
2
8
83h 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 MODULATION and recalled from Table 04h at the adjusted memory address found in
TINDEX. This register is updated at the end of the temperature conversion.
Table 02h, Register 82h–83h: MODULATION REGISTER