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BR25H080-2C Datasheet, PDF (20/35 Pages) Rohm – Serial EEPROM Series Automotive EEPROM 125 Operation SPI BUS EEPROM | |||
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BR25H080-2C
Datasheet
âAt standby
âCurrent at standby
Set CSB âHâ, and be sure to set SCK, SI, WPB, HOLDB input âLâ or âHâ. Do not input intermediate electric potential.
âTiming
As shown in Figure.43, at standby, when SCK is âHâ, even if CSB is fallen, SI status is not read at fall edge. SI status is
read at SCK rise edge after fall of CSB. At standby and at power ON/OFF, set CSB âHâ status.
CSB
SCK
Even if CSB is fallen at SCK=SI=âHâ,
SI status is not read at that edge.
Command start here. SI is read.
0
1
2
SI
Figure 43. Operating timing
âWPB cancel valid area
WPB is normally fixed to âHâ or âLâ for use, but when WPB is controlled so as to cancel write status register command and
write command, pay attention to the following WPB valid timing.
While write or write status register command is executed, by setting WPB = âLâ in cancel valid area, command can be
cancelled. The Data area (from 7clock fall to 16clock rise) becomes the cancel valid area. However, once write is started, any
input cannot be cancelled. WPB input becomes Donât Care, and cancellation becomes invalid.
CSB
SCK
6
7
Ope Code
15
Data
16
tE/W
Data write time
In val id
Valid
Invali d
Figure 44. WPB valid timing (WRSR)
CSB
SCK
6
7
Ope code
8
23
Address
31
Data
32
tE/W
Data write time
Invalid
Invalid
Invalid
Invalid
Figure 45. WPB valid timing (WRITE)
âHOLDB pin
By HOLDB pin, command communication can be stopped temporarily (HOLD status). The HOLDB pin carries out command
communications normally when it is HIGH. To get in HOLD status, at command communication, when SCK=LOW, set the
HOLDB pin LOW. At HOLD status, SCK and SI become Donât Care, and SO becomes high impedance (High-Z). To release
the HOLD status, set the HOLDB pin HIGH when SCK=LOW. After that, communication can be restarted from the point
before the HOLD status. For example, when HOLD status is made after A5 address input at read, after release of HOLD
status, by starting A4 address input, read can be restarted. When in HOLD status, leave CSB LOW. When it is set
CSB=HIGH in HOLD status, the IC is reset, therefore communication after that cannot be restarted.
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TSZ02201-0R1R0G100100-1-2
21.Mar.2013 Rev.001
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