E 2 Prom Functions; Fig. 5.4.2 Byte Write Timing; Fig. 5.4.3 Random Address Read Timing - Renesas 7200 Series User Manual

APPLICATION
5.4 Example of I 2
2
5.4.3 E PROM functions
(1) Byte write
Bytes are written by sending the START condition, slave address "A0
(1 byte), and the STOP condition from the master. Writing to the E
master sends the STOP condition, that is, in synchronization with a rising edge of the SDA signal.
This writing will be automatically terminated by the on-chip sequential controller. In this period, no
acknowledge bits are generated.
Figure 5.4.2 shows the byte write timing.
Bus operation of
master side:
SDA signal S
Bus operation of
slave side:

Fig. 5.4.2 Byte write timing

(2) Random address read
In this mode, the data of an arbitrary address is read. To set the first-read address, the master sends
the START condition, slave address "A0
bit (ACK) from the E
"A1 " again. After ACK is generated from the E
16
is read out.
After the data is output, no acknowledge bits are generated, but the STOP condition is sent by the
master, completing this read operation.
S
T
Bus operation of
A
R
master side:
T
SDA signal S
Bus operation of
slave side:
ACK

Fig. 5.4.3 Random address read timing

5-22
C-BUS interface control (M37221Mx-XXXSP/FP)
S
T
Slave
A
address (W)
R
T
S : START condition
P : STOP condition
ACK : Acknowledge bit
W : Write bit (0)
2 PROM, the master sends the RESTART condition signal and slave address
Slave
address (W) Sub-address (n)
W
A
C
K
S : START condition
P : STOP condition
: Acknowledge bit
W : Write bit (0)
7220 Group User's Manual
Sub-address (n)
W
A
C
K
," and sub-address (1 byte). Upon receiving the acknowledge
16
2 PROM, the data of the corresponding sub-address
S
T
A
Slave address (R)
R
T
R
S
A
C
K
R : Read bit (1)
RS : RESTART condition
NACK
: No acknowledge bit
," sub-address (1 byte), data
16
2
PROM will be started after the
S
T
Data (n)
O
P
P
A A
C C
K K
R
A
C
Data (n)
K
N
A
S
C
T
K
O
P
P