Datasheet
26 Maxim Integrated
SFP Controller for Dual Rx Interface
DS1877
Lower Memory Register Map
<C> or <_/C> = Common, <D> or <_/D> = Different, <M> or <_/M> = Mixture of common and different.
Table 01h Register Map
<C> or <_/C> = Common, <D> or <_/D> = Different, <M> or <_/M> = Mixture of common and different.
Note: The ALARM ENABLE bytes (Registers F8h−FFh) can be configured to exist in Table 05h instead of here at Table 01h with
the MASK bit (Table 02h, Register 88h). If the row is configured to exist in Table 05h, these locations are empty in Table 01h.
The access codes represent the factory default values of PW_ENA and PW_ENB (Table 02h, Registers C0h−C1h).
These registers also allow for custom permissions.
LOWER MEMORY
ROW
(HEX)
ROW NAME
WORD 0 WORD 1 WORD 2 WORD 3
BYTE 0/8 BYTE 1/9 BYTE 2/A BYTE 3/B BYTE 4/C BYTE 5/D BYTE 6/E BYTE 7/F
00–07
<1/C>
THRESHOLD
0
TEMP ALARM HI TEMP ALARM LO TEMP WARN HI TEMP WARN LO
08–0F
<1/C >
THRESHOLD
1
V
CC
ALARM HI V
CC
ALARM LO V
CC
WARN HI V
CC
WARN LO
10–1F
<1/C>
EEPROM EE EE EE EE
20–27
<1/D>
THRESHOLD
4
RSSI ALARM HI RSSI ALARM LO RSSI WARN HI RSSI WARN LO
28–37
<1/C >
EEPROM EE EE EE EE
38–4F
<1/D >
EEPROM EE EE EE EE
50–5F
<1/C >
EEPROM EE EE EE EE EE EE EE EE
60–67
<2/C>
ADC VALUES
0
TEMP VALUE V
CC
VALUE RESERVED RESERVED
68–6F
<0/M>
ADC VALUES
1
<2/D>
RSSI VALUE RESERVED RESERVED
<0/M>
STATUS
<3/D>
UPDATE
70–77
<2/D>
ALARM/WARN ALARM
3
ALARM
2
RESERVED ALARM
0
WARN
3
RESERVED RESERVED RESERVED
78–7F
<0/M>
TABLE SELECT RESERVED RESERVED RESERVED
<6/C>
PWE MSW
<6/C>
PWE LSW
<5/D>
TBL SEL
TABLE 01h
ROW
(HEX)
ROW NAME
WORD 0 WORD 1 WORD 2 WORD 3
BYTE 0/8 BYTE 1/9 BYTE 2/A BYTE 3/B BYTE 4/C BYTE 5/D BYTE 6/E BYTE 7/F
80–BF
<7/C>
EEPROM EE EE EE EE EE EE EE EE
C0–F7
<8/C>
EEPROM EE EE EE EE EE EE EE EE
F8–FF
<7/M>
ALARM ENABLE
<C>
ALARM EN
3
<D>
ALARM EN
2
RESERVED
<D>
ALARM EN
0
<C>
WARN EN
3
RESERVED RESERVED RESERVED
ACCESS
CODE
<0/_> <1/_> <2/_> <3/_> <4/_> <5/_> <6/_> <7/_> <8/_> <9/_> <10/_> <11/_>
Read
Access
See each
bit/byte
separately
All All All PW2 All N/A PW1 PW2 N/A PW2 All
Write
Access
PW2 N/A
All and
DS1877
hardware
PW2 +
mode
bit
All All PW1 PW2 PW2 N/A PW1