BR24A16-WM(2009) 데이터 시트보기 (PDF) - ROHM Semiconductor
부품명
상세내역
제조사
BR24A16-WM Datasheet PDF : 18 Pages
| |||
BR24A□□-WM series
Technical Note
●Software reset
Software reset is executed when to avoid malfunction after power on, and to reset during command input. Software reset
has several kinds, and 3 kinds of them are shown in the figure below. (Refer to Fig.47(a), Fig.47(b), and Fig.47(c).) In
dummy clock input area, release the SDA bus ('H' by pull up). In dummy clock area, ACK output and read data '0' (both 'L'
level) may be output from EEPROM, therefore, if 'H' is input forcibly, output may conflict and over current may flow, leading
to instantaneous power failure of system power source or influence upon devices.
SCL
SDA
Dummy clock×14
Start×2
12
13 14
Normal command
Normal command
Fig.47-(a) The case of dummy clock +START+START+ command input
SCL
SDA
Start
1
Dummy clock×9
2
8
Start
9
Normal command
Normal command
Fig.47-(b) The case of START +9 dummy clocks +START+ command input
SCL
SDA
Start×9
1 23
7 89
Normal command
Normal command
Fig.47-(c) START×9+ command input
※ Start command from START input.
●Acknowledge polling
During internal write execution, all input commands are ignored, therefore ACK is not sent back. During internal automatic
write execution after write cycle input, next command (slave address) is sent, and if the first ACK signal sends back 'L', then
it means end of write action, while if it sends back 'H', it means now in writing. By use of acknowledge polling, next
command can be executed without waiting for tWR = 5ms.
When to write continuously, R/W = 0, when to carry out current read cycle after write, slave address R/W = 1 is sent, and if
ACK signal sends back 'L', then execute word address input and data output and so forth.
First write command
During internal write,
ACK = HIGH is sent back.
S
T
A
R
T
S
Write command
T
O
P
S
T Slave
A
R address
T
A
C
K
H
S
T
A
Slave
R address
T
A
C
K
H
tWR
Second write command
…
S
T Slave
A
R
address
T
A
C
K
H
tWR
S
T Slave
A
R address
T
A
C
Word
K
L
address
A
C
K
Data
L
AS
CT
KO
LP
After completion of internal write,
ACK=LOW is sent back, so input next
word address and data in succession.
Fig.48 Case to continuously write by acknowledge polling
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
11/17
2009.08 - Rev.C
Share Link: 