DS2431/T&R Maxim Integrated, DS2431/T&R Datasheet - Page 22

• Manufacturer Part Number: DS2431/T&R
• Description: EEPROM
• Manufacturer: Maxim Integrated

Specifications of DS2431/T&R

• Memory Size: 1 Kbit
• Organization: 4 Pages x 256
• Data Retention: 40 Years
• Operating Supply Voltage: 3.3 V, 5 V
• Maximum Operating Temperature: + 85 C
• Package / Case: TO-92
• Interface Type: 1-Wire Serial
• Minimum Operating Temperature: - 40 C
• Supply Voltage - Max: 5.25 V
• Supply Voltage - Min: 2.8 V

1024-Bit, 1-Wire EEPROM
Write to the first 8 bytes of memory page 1. Read the
entire memory.
DS2431
22
MASTER MODE
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
—
Memory Function Example
DATA (LSB FIRST)
<2 Bytes CRC-16>
<2 Bytes CRC-16>
<1-Wire Idle High>
<144 Data Bytes>
<8 Data Bytes>
<8 Data Bytes>
(Presence)
(Presence)
(Presence)
(Presence)
(Presence)
(Reset)
(Reset)
(Reset)
(Reset)
(Reset)
CCh
CCh
AAh
CCh
AAh
CCh
0Fh
20h
00h
20h
00h
07h
55h
20h
00h
07h
F0h
00h
00h
With only a single DS2431 connected to the bus mas-
ter, the communication looks like this:
Reset pulse
Presence pulse
Issue “Skip ROM” command
Write 8 bytes of data to scratchpad
Read CRC to check for data integrity
Reset pulse
Presence pulse
Issue “Skip ROM” command
Issue “Read Scratchpad” command
Read scratchpad data and verify
Read CRC to check for data integrity
Reset pulse
Presence pulse
Issue “Skip ROM” command
Issue “Copy Scratchpad” command
TA1
TA2
E/S
Reset pulse
Presence pulse
Issue “Skip ROM” command
Issue “Read Memory” command
Read the entire memory
Reset pulse
Presence pulse
Issue “Write Scratchpad” command
TA1, beginning offset = 20h
TA2, address = 0020h
Read TA1, beginning offset = 20h
Read TA2, address = 0020h
Read E/S, ending offset = 111b, AA, PF = 0
Wait t
Read copy status, AAh = success
TA1, beginning offset = 00h
TA2, address = 0000h
PROGMAX
(AUTHORIZATION CODE)
for the copy function to complete
COMMENTS
Maxim Integrated