Datasheet

39Maxim Integrated
SFP Controller for Dual Rx Interface
DS1877
Lower Memory, Register 7Fh: TABLE SELECT (TBL SEL)
Lower Memory, Registers 75h–7Ah: RESERVED
Lower Memory, Registers 7Bh–7Eh: PASSWORD ENTRY (PWE)
POWER-ON VALUE 00h
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 locations
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 device. 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.
POWER-ON VALUE TBLSELPON (Table 02h, Register C7h)
READ ACCESS All
WRITE ACCESS All
A2h AND B2h MEMORY Different A2h and B2h memory locations
MEMORY TYPE Volatile
7Fh 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT 7 BIT 0
The upper memory tables of the device are accessible by writing the desired table value in this register. The power-
on value of this register is defined by the value written to TBLSELPON (Table 02h, Register C7h).