Read Mode Sequences; Read Operations; Random Address Read; Current Address Read - Harman Kardon AVR145 Service Manual

AVR145
M24C64, M24C32
Figure 10. Read Mode Sequences
CURRENT
ADDRESS
READ
RANDOM
ADDRESS
READ
SEQUENTIAL
CURRENT
READ
SEQUENTIAL
RANDOM
READ
Note: 1. The seven most significant bits of the Device Select Code of a Random Read (in the 1

Read Operations

Read operations are performed independently of
the state of the Write Control (WC) signal.
After the successful completion of a Read opera-
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
10.) but without sending a Stop condition.
ure
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-
ACK NO ACK
DEV SEL DATA OUT
R/W
ACK ACK
DEV SEL * BYTE ADDR
R/W
ACK ACK
DEV SEL DATA OUT 1
R/W
ACK ACK
DEV SEL * BYTE ADDR
R/W
ACK NO ACK
DATA OUT N
Fig-
139
ACK ACK
BYTE ADDR DEV SEL *
R/W
ACK NO ACK
DATA OUT N
ACK ACK
BYTE ADDR DEV SEL *
R/W
st th
and 4
dressed byte. The
acknowledge the byte, and terminates the transfer
with a Stop condition.

Current Address Read

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
ing the byte.
harman/kardon
NO ACK
DATA OUT
ACK
DATA OUT 1
AI01105C
bytes) must be identical.
bus master must not
10., without acknowledg-