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Ds1875 pon triplexer and sfp controller – Rainbow Electronics DS1875 User Manual

Page 62

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DS1875

PON Triplexer and SFP Controller

62

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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