BU99022NUX-3 Datasheet, PDF (14/26 Pages) Rohm – I2C BUS 2kbit + 2kbit 2ports serial EEPROM

BU99022NUX-3
Datasheet
●Write Command
○Write cycle
・Arbitrary data is written to EEPROM. When to write only 1 byte, byte write is normally used, and when to write continuous data of 2 bytes
or more, simultaneous write is possible by page write cycle. The maximum number of write bytes is up to 8.
SDA
LIN E
S
W
T
R
A
I
R
SLAVE
T
T
ADDRESS E
W ORD
ADDRESS
DATA
1010000
WA
7
RA
/C
WK
WA
0
D7
A
C
K
Fig.36 Byte write cycle (port1 EEPROM)
S
T
O
P
D0
A
C
K
SDA
LIN E
SDA
LINE
S
W
T
R
A
I
R
SLAVE
T
T
ADDRESS E
W ORD
ADDRESS
S
T
DATA
O
P
1 0 1 0 ＊＊＊
WA
7
WA
0
D7
RA
A
/C
C
WK
K
Fig.37 Byte write cycle (port2 EEPROM)
D0
A
C
K
* D on’t C are
S
W
T
R
A
SLAVE
I
R
ADDRESS
T
T
E
WORD
ADDRESS(n)
DATA(n)
1 0 1 _{00 00}
WA
WA ^D7
D0
7
0
S
DATA(n+15)
T
O
P
D0
RA
A
A
/C
C
C
W K _{Fig.38 Page writ}K_{e cycle (port1 EEPRO}^K _M)
A
C
K
*Don’t Care
S
W
T
R
A
I
R
SLAVE
T
ADDRESS
T
E
WORD
ADDRESS(n)
DATA(n)
SDA
LINE
1 0 1 _{0* **}
WA
7
WA ^D7
0
D0
S
DATA(n+15)
T
O
P
D0
RA
A
A
/C
C
C
WK
K
K
Fig.39 Page write cycle (port2 EEPROM)
A
C
K
*Don’t Care
・During internal write execution, all input commands are ignored, therefore ACK is not sent back.
・Data is written to the address designated by word address (n-th address)
・By issuing stop bit after 8bit data input, write to memory cell inside starts.
・When internal write is started, command is not accepted for tWR (5ms at maximum).
・By page write cycle, the following can be written in bulk :
And when data of the maximum bytes or higher is sent, data from the first byte is overwritten.
・As for page write cycle , after the significant 5 bits of word address are designated arbitrarily, by continuing data input of
2 bytes or more, the address of insignificant 3 bits is incremented internally, and data up to 8 bytes can be written.
○Write protect (WP2) terminal
・Write protect (WP2) function
When WP2 terminal is set Vcc (H level), data rewrite of all addresses is prohibited (only port2 EEPROM).
When it is set GND (L level), data rewrite of all address is enabled. Be sure to connect this terminal to Vcc or GND,
or control it to H level or L level. Do not use it open.
In the case of use it as an ROM, it is recommended to connect it to pull up or Vcc.
At extremely low voltage at power ON / OFF, by setting the WP terminal 'H', mistake write can be prevented.
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TSZ22111・14・001
14/23
TSZ02201-0R2R0G100010-1-2
2011.12.19 Rev.001