DS2431 Maxim, DS2431 Datasheet - Page 7

• Manufacturer Part Number: DS2431
• Description: The DS2431 is a 1024-bit, 1-Wire® EEPROM chip organized as four memory pages of 256 bits each
• Manufacturer: Maxim

Data memory and registers are located in a linear
address space, as shown in Figure 5. The data memo-
ry and the registers have unrestricted read access.
The DS2431 EEPROM array consists of 18 rows of 8
bytes each. The first 16 rows are divided equally into
four memory pages (32 bytes each). These four pages
are the primary data memory. Each page can be indi-
vidually set to open (unprotected), write protected, or
Figure 4. 1-Wire CRC Generator
Figure 5. Memory Map
* Once programmed to AAh or 55h this address becomes read only. All other codes can be stored, but neither write protect the
address nor activate any function.
X
ADDRESS RANGE
0
0000h to 001Fh
0020h to 003Fh
0040h to 005Fh
0060h to 007Fh
0088h to 008Fh
STAGE
1ST
0080h*
0081h*
0082h*
0083h*
0084h*
0085h
0086h
0087h
X
1
_______________________________________________________________________________________
STAGE
2ND
X
2
TYPE
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
R/(W)
—
R
STAGE
3RD
Memory Access
Data Memory Page 0
Data Memory Page 1
Data Memory Page 2
Data Memory Page 3
Protection Control Byte Page 0
Protection Control Byte Page 1
Protection Control Byte Page 2
Protection Control Byte Page 3
Copy Protection Byte
Factory Byte. Set at Factory.
User Byte/Manufacturer ID
User Byte/Manufacturer ID
Reserved
X
3
STAGE
4TH
DESCRIPTION
POLYNOMIAL = X
1024-Bit, 1-Wire EEPROM
X
4
8
+ X
5
STAGE
EPROM mode by setting the associated protection
byte in the register row. As a factory default, the entire
data memory is unprotected and its contents are unde-
fined. The last two rows contain protection registers
and reserved bytes. The register row consists of 4 pro-
tection control bytes, a copy-protection byte, the facto-
ry byte, and 2 user byte/manufacture ID bytes. The
manufacturer ID can be a customer-supplied identifi-
cation code that assists the application software in
identifying the product the DS2431 is associated with.
5TH
+ X
4
+ 1
—
—
—
—
55h: Write Protect P0; AAh: EPROM Mode P0;
55h or AAh: Write Protect 80h
55h: Write Protect P1; AAh: EPROM Mode P1;
55h or AAh: Write Protect 81h
55h: Write Protect P2; AAh: EPROM Mode P2;
55h or AAh: Write Protect 82h
55h: Write Protect P3; AAh: EPROM Mode P3;
55h or AAh: Write Protect 83h
55h or AAh: Copy Protect 0080h:008Fh, and Any
Write-Protected Pages
AAh: Write Protect 85h, 86h, 87h;
55h: Write Protect 85h; Unprotect 86h, 87h
—
—
—
X
5
PROTECTION CODES
STAGE
6TH
X
6
STAGE
7TH
X
INPUT DATA
7
STAGE
8TH
X
8
7