BU9889GUL-W Rohm, BU9889GUL-W Datasheet - Page 10

• Manufacturer Part Number: BU9889GUL-W
• Description: WL-CSP EEPROM family I2C BUS
• Manufacturer: Rohm

●Read Command
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BU9889GUL-W
www.rohm.com
・Read cycle is ended by stop condition where 'H' is input to ACK signal after D0 and SDA signal is started at SCL signal 'H'.
○Read cycle
・In random read cycle, data of designated word address can be read.
・When the command just before current read cycle is random read cycle, current read cycle (each including sequential
・When ACK signal 'LOW' after D0 is detected, and stop condition is not sent from master (µ-COM) side, the next address
・When 'H' is not input to ACK signal after D0, sequential read gets in, and the next data is output.
・Sequential read is ended by stop condition where 'H' is input to ACK signal after arbitrary D0 and SDA is started at SCL
Data of EEPROM is read. In read cycle, there are random read cycle and current read cycle.
Random read cycle is a command to read data by designating address, and is used generally.
Current read cycle is a command to read data of internal address register without designating address, and is used when
to verify just after write cycle. In both the read cycles, sequential read cycle is available, and the next address data can
be read in succession.
read cycle), data of incremented last read address (n)-th address, i.e., data of the (n+1)-th address is output.
data can be read in succession.
Therefore, read command cycle cannot be ended. When to end read command cycle, be sure input stop condition to
input 'H' to ACK signal after D0, and to start SDA at SCL signal 'H'.
signal 'H'.
SD A
LINE
SDA
LINE
SDA
LINE
R
S
T
A
T
Fig.37 Sequential read cycle (in the case of current read cycle)
S
T
A
R
T
1 0
1 0
S
A
R
T
T
A DDRE SS
Fig.35 Random read cycle
Fig.36 Current read cycle
S LA VE
1 0
ADDRESS
1
SLAVE
1
AD DRES S
0
0
S LAV E
A2
1
A2
P1
0
P1
P0
A 2
P0
W
W
R
E
R
T
I
/
P 1
R
E
A
D
R
/
W
C
A
K
P 0
C
A
K
W A
7
D7
W
R
D
R
E
A
/
ADD RES S(n)
C
A
K
W O RD
D7
DATA(n)
DA TA (n)
W A
0
D0
A
C
K
A
C
K
S
T
A
R
T
1 0
D0
A DDRE SS
SLA VE
A
C
K
1
O
0
S
T
P
A 2
P1
P0
W
R
E
A
D
R
/
A
C
K
C
A
K
D7
D7
10/17
DATA(n+x)
DA TA (n)
D0
D0
A
C
K
C
A
K
S
T
O
P
O
S
T
P
It is necessary to input 'H'
to the last ACK.
It is necessary to input 'H'
to the last ACK.
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2010.01 - Rev.A
Technical Note