Ds1876 sfp controller with dual ldd interface – Rainbow Electronics DS1876 User Manual
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DS1876
SFP Controller with Dual LDD Interface
Lower Memory, Registers 75h–7Ah: RESERVED MEMORY
Lower Memory, Registers 7Bh–7Eh: PASSWORD ENTRY (PWE)
POWER-ON VALUE
READ ACCESS
N/A
WRITE ACCESS
N/A
A2h AND B2h MEMORY
N/A
MEMORY TYPE
N/A
These registers are reserved. The value when read is 00h.
POWER-ON VALUE
FFFF FFFFh
READ ACCESS
N/A
WRITE ACCESS
All
A2h AND B2h MEMORY
Common A2h and B2h memory location
MEMORY TYPE
Volatile
7Bh
2
31
2
30
2
29
2
28
2
27
2
26
2
25
2
24
7Ch
2
23
2
22
2
21
2
20
2
19
2
18
2
17
2
16
7Dh
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
7Eh
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT 7
BIT 0
There are two passwords for the DS1876. Each password is 4 bytes long. The lower level password (PW1) has
all the access of a normal user plus those made available with PW1. The higher level password (PW2) has all the
access of PW1 plus those made available with PW2. The values of the passwords reside in EEPROM inside PW2
memory. At power-up, all PWE bits are set to 1. All reads at this location are 0.