AT34C02-10PU-1.8 ATMEL [ATMEL Corporation], AT34C02-10PU-1.8 Datasheet - Page 11
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AT34C02-10PU-1.8
Manufacturer Part Number
AT34C02-10PU-1.8
Description
Two-wire Serial EEPROM with Permanent Software Write Protect
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT34C02-10PU-1.8.pdf
(21 pages)
Read Operations
0958Q–SEEPR–1/07
WP Connected to GND or Floating
WP Connected to V
Start
1010
1010
1010
1010
1010
1010
0110
0110
0110
0110
0110
0110
0110
0110
R/W Bit
W
W
W
W
W
W
W
W
R
R
R
R
R
R
Write Protect Register
CC
Not Programmed
Not Programmed
Not Programmed
Not Programmed
Not Programmed
Not Programmed
Programmed
Programmed
Programmed
Programmed
Programmed
Programmed
X
X
Figure 7. Setting Write Protect Register
Read operations are initiated the same way as write operations with the exception that
the read/write select bit in the device address word is set to one. There are three read
operations: current address read, random address read and sequential read.
CURRENT ADDRESS READ: The internal data word address counter maintains the
last address accessed during the last read or write operation, incremented by one. This
address stays valid between operations as long as the chip power is maintained. The
address “roll over” during read is from the last byte of the last memory page to the first
byte of the first page.
Once the device address with the read/write select bit set to one is clocked in and
acknowledged by the EEPROM, the current address data word is serially clocked out.
To end the command, the microcontroller does not respond with an input zero but does
generate a following stop condition (see Figure 11 on page 13).
RANDOM READ: A random read requires a “dummy” byte write sequence to load in the
data word address. Once the device address word and data word address are clocked
SDA LINE
Acknowledgment
from Device
No ACK
No ACK
No ACK
No ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
R
S
T
A
T
0 1 1 0
CONTROL
Action from Device
Read Array
Can Write to Second Half (80H - FFH) Only
Can Write to Full Array
Stop - Indicates Write Protect Register is Programmed
Read Out Data Don’t Care. Indicates WP Register is Not Prog
Stop - Indicates Write Protect Register is Programmed
Program Write Protect Register (irreversible)
Read Array
Device Write Protect
Device Write Protect
Stop - Indicates Write Protect Register is Programmed
Read Out Data Don’t Care. Indicates WP Register is Not Prog
Stop - Indicates Write Protect Register is Programmed
Cannot Program Write Protect Register
BYTE
0
C
A
K
ADDRESS
= Don't Care
WORD
A
C
K
DATA
A
C
K
S
O
P
T
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