M24C64 Datasheet, PDF (12/26 Pages) STMicroelectronics – 64/32 Kbit Serial I²C Bus EEPROM

M24C64, M24C32
Figure 10. Read Mode Sequences
CURRENT
ADDRESS
READ
ACK
NO ACK
DEV SEL
DATA OUT
R/W
RANDOM
ADDRESS
READ
ACK
ACK
ACK
ACK
NO ACK
DEV SEL *
BYTE ADDR BYTE ADDR
DEV SEL *
DATA OUT
R/W
R/W
SEQUENTIAL
CURRENT
READ
SEQUENTIAL
RANDOM
READ
ACK
ACK
DEV SEL
DATA OUT 1
R/W
ACK
NO ACK
DATA OUT N
ACK
ACK
ACK
ACK
ACK
DEV SEL *
BYTE ADDR BYTE ADDR
DEV SEL *
DATA OUT 1
R/W
R/W
ACK
NO ACK
DATA OUT N
AI01105C
Note: 1. The seven most significant bits of the Device Select Code of a Random Read (in the 1^st and 4^th bytes) must be identical.
Read Operations
Read operations are performed independently of
the state of the Write Control (WC) signal.
dressed byte. The bus master must not
acknowledge the byte, and terminates the transfer
with a Stop condition.
After the successful completion of a Read opera- ^{Current Address Read}
tion, the device’s internal address counter is incre-
mented by one, to point to the next byte address.
Random Address Read
A dummy Write is first performed to load the ad-
dress into this address counter (as shown in Fig-
ure 10.) but without sending a Stop condition.
Then, the bus master sends another Start condi-
tion, and repeats the Device Select Code, with the
Read/Write bit (RW) set to 1. The device acknowl-
edges this, and outputs the contents of the ad-
For the Current Address Read operation, following
a Start condition, the bus master only sends a De-
vice Select Code with the Read/Write bit (RW) set
to 1. The device acknowledges this, and outputs
the byte addressed by the internal address
counter. The counter is then incremented. The bus
master terminates the transfer with a Stop condi-
tion, as shown in Figure 10., without acknowledg-
ing the byte.
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