DS1875T+ Maxim Integrated Products, DS1875T+ Datasheet - Page 32

• Manufacturer Part Number: DS1875T+
• Description: IC SFP CTRLR/TRIPLEXER 38-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of DS1875T+

• Applications: Fiber Optics
• Interface: I²C
• Voltage - Supply: 2.85 V ~ 3.9 V
• Package / Case: *
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PON Triplexer and SFP Controller
Many NV memory locations (listed within the Register
Descriptions section) are actually shadowed EEPROM
that are controlled by the SEEB bit in Table 02h, Byte
80h.
The DS1875 incorporates shadowed-EEPROM memory
locations for key memory addresses that can be written
many times. By default the shadowed-EEPROM bit,
SEEB, is not set and these locations act as ordinary
EEPROM. By setting SEEB, these locations function like
SRAM cells, which allow an infinite number of write
Figure 16. Memory Map
32
DEC
255
0
HEX
FFh
0h
______________________________________________________________________________________
00h
I
2
AUXILIARY MEMORY
C SLAVE ADDRESS A0h
EEPROM
(FIXED)
FFh
DEC
128
255
HEX
80h
FFh
80h
89h
MON5–MON8 CONV
NO MEMORY
TABLE 00h
Shadowed EEPROM
88h
FFh
80h
F8h
PW1 LEVEL ACCESS
(120 BYTES)
TABLE 01h
EEPROM
ATB
FFh
F7h
80h
D8h
F8h
CONFIGURATION AND
MISC. CONTROL
NO MEMORY
TABLE 02h
CONTROL
BITS
D7h
F7h
FFh
cycles without concern of wearing out the EEPROM.
This also eliminates the requirement for the EEPROM
write time, t
abled do not affect the EEPROM, these changes are
not retained through power cycles. The power-on value
is the last value written with SEEB enabled. This func-
tion can be used to limit the number of EEPROM writes
during calibration or to change the monitor thresholds
periodically during normal operation helping to reduce
the number of times EEPROM is written. The Memory
Map description indicates which locations are shad-
owed EEPROM.
80h
PW2 LEVEL ACCESS
00h
30h
60h
PASSWORD ENTRY (PWE)
TABLE SELECT BYTE
(128 BYTES)
I
TABLE 03h
2
C SLAVE ADDRESS A2h
EEPROM
DIGITAL DIAGNOSTIC
DIGITAL DIAGNOSTIC
PW2 LEVEL ACCESS
LOWER MEMORY
FUNCTIONS
FUNCTIONS
(DEFAULT)
(48 BYTES)
(7Bh–Eh)
EEPROM
FFh
WR
7Ah
2Fh
5Fh
7Fh
. Because changes made with SEEB dis-
80h
MODULATION
TABLE 04h
LUT
C7h
80h
TABLE 05h
APC TE LUT
A3h
80h
M4DAC LUT
TABLE 06h
9Fh
80h
PWM REF LUT
TABLE 07h
A3h
80h
TABLE 08h
OPEN-LOOP
BIAS
LUT
C7h