BU9831 Datasheet, PDF (10/13 Pages) Rohm – Non-volatile electronic potentiometer

Memory ICs
BU9831 / BU9831F
(5) Data write (DWR)
H
SK
1
4
L
H
CS
L
8
16
32
H
DIO
L
1 0 1 0 0 1 0 0 A0
A6
D0
D15
tE/W
Fig. 15 Data write
1) This command stores the input data in the address specified by A0 to A6.
2) CS must be LOW during the write mode input, but once writing begins, CS may be either HIGH or LOW.
3) The internal timer circuit in the IC begins to function after the rising edge of the SK at which the last data D0 was
read, and data is written to memory cells during the time period tE / W. The process is terminated automatically.
At this point, the SK input during the tE / W time period may be either HIGH or LOW.
4) The time period between input of this command and the automatic termination of the writing of data is the time
during which data is written to the internal non-volatile memory, so commands input during this interval will not be
accepted. The maximum time interval must be within tE / W.
5) After the write command has been input, if CS is set to LOW after having been set to HIGH, command reception
is enabled following termination of the automatic data writing. Data can then be received from SK and DIO. If CS is
left at LOW following input of the command, however, without being set to HIGH, input of the command is canceled.
(6) Transmission memory data read (TDWR)
H
SK
1
4
8
L
H
CS
L
H
DIO
L
0
1
0
1
0
1 00 1
A0
16
A6
VW
t AW
Fig. 16 Transmission memory data read
1) This command transmits the data from the addresses specified by A0 to A6 to the wiper counter. The wiper
moves to the position indicated by the seven bits D8 to D14 of the specified address, and the resistance value stabi-
lizes after the tAW time period starting with the fall of the 15th clock. Data subsequent to the 16th clock is ignored.
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