BU99901GUZ-W ROHM Co. Ltd., BU99901GUZ-W Datasheet - Page 9

• Manufacturer Part Number: BU99901GUZ-W
• Description: 4k?8 Bit Electrically Erasable Prom
• Manufacturer: ROHM Co. Ltd.

◇BYTE WRITE
○By using this command, the data is programed into the indicated word address.
○When the master generates a STOP condition, the device begins the internal
○ACKNOWLEDGE
write cycle to the nonvolatile memory array.
・Acknowledge is a software convention used to indicate successful data transfers.
(When inputting the slave address in the write or read operation, transmitter is μ-COM.
・During the ninth clock cycle, the receiver will pull the SDA line LOW to acknowledge
・The device will respond with an Acknowledge after recognition of a START condition
・In the WRITE mode, the device will respond with an Acknowledge, after the receipt of
・In the READ mode, the device will transmit eight bit of data, release the SDA line,
・If an Acknowledge is detected, and no STOP condition is generated by the master,
The transmitter device will release the bus after transmitting eight bits.
When outputting the data in the read operation, it is this device.)
that the eight bits of data has been received.
and its slave address (8bit).
each subsequent 8-bit word (word address and write data).
and monitor the line for an Acknowledge.
the device will continue to transmit the data.
If an Acknowledge is not detected, the device will terminate further data transmissions
and await a STOP condition before returning to the standby mode.
(When inputting the slave address in the write or read operation, receiver is this
device. When outputting the data in the read operation, it is μ-COM.)
(See Fig.-7 ACKNOWLEDGE RESPONSE FROM RECEIVER)
（Fromμ-COM）
（μ-COM
（IC OUTPUT DATA）
OUTPUT DATA)
SCL
SDA
SDA
SDA
LINE
WP
Fig.-7 ACKNOWLEDGE RESPONSE FROM RECEIVER
START CONDITION
(START BIT)
S
T
A
R
T
1 0
ADDRESS
SLAVE
1
0
0
Fig.-8 BYTE WRITE CYCLE TIMING
0
0
1
W
W
R
T
E
R
/
I
A
C
K
* * *
1st WORD
ADDRESS
*
REV. A
WA
11
A
C
K
2nd WORD
ADDRESS
8
WA
Acknowledge Signal
0
(ACK Signal)
A
C
K
D7
9
DATA
* : Don’t care
D0
A
C
K
O
P
S
T
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