Rainbow Electronics DS1874 - Manual (Page 55)

DS1874
SFP+ Controller with Digital LDD Interface
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Table 02h Register Descriptions
Table 02h, Register 80h: MODE
POWER-ON VALUE 3Fh
READ ACCESS PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
WRITE ACCESS PW2 or (PW1 and RTBL246)
MEMORY TYPE Volatile
80h SEEB RESERVED DAC1 EN DAC2 EN AEN MOD EN APC EN BIAS EN
BIT 7 BIT 0
BIT 7
SEEB:
0 = (Default) Enables EEPROM writes to SEE bytes.
1 = Disables EEPROM writes to SEE bytes during configuration, so that the configuration of the part
is not delayed by the EE cycle time. Once the values are known, write this bit to a 0 and write the
SEE locations again for data to be written to the EEPROM.
BIT 6 RESERVED
BIT 5
DAC1 EN:
0 = DAC1 VALUE is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the values for DAC1. The output is updated with the new
value at the end of the write cycle. The I
2 C STOP condition is the end of the write cycle.
1 = (Default) Enables auto control of the LUT for DAC1 VALUE.
BIT 4
DAC2 EN:
0 = DAC2 VALUE is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the values for DAC2. The output is updated with the new
value at the end of the write cycle. The I
2 C STOP condition is the end of the write cycle.
1 = (Default) Enables auto control of the LUT for DAC2 VALUE.
BIT 3
AEN:
0 = The temperature-calculated index value TINDEX is writable by users and the updates of
calculated indexes are disabled. This allows users to interactively test their modules by
controlling the indexing for the LUTs. The recalled values from the LUTs appear in the DAC
registers after the next completion of a temperature conversion.
BIT 2
MOD EN:
0 = Modulation is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the DAC value for modulation. The output is updated with the
new value at the end of the write cycle. The I
2 C STOP condition is the end of the write cycle.
1 = (Default) Enables auto control of the LUT for modulation.
BIT 1
APC EN:
0 = APC DAC is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the DAC value for APC reference. The output is updated with
the new value at the end of the write cycle through the 3-wire interface. The I
2 C STOP condition is the
end of the write cycle.
1 = (Default) Enables auto control of the LUT for APC reference.
BIT 0
BIAS EN:
0 = BIAS register is controlled by the user and the APC is in manual mode. The BIAS register value
is written with the use of the 3-wire interface. This allows the user to interactively test their modules
by writing the DAC value for bias.
1 = (Default) Enables auto control for the APC feedback.