BR9010-W / F-W / FV-W / RFV-W / RFVM-W / BR9020-W / F-W / FV-W /
Memory IC
RFV-W / RFVM-W / BR9040-W / F-W / FV-W / RFV-W / RFVM-W
11/14
1) During the write instruction , CS must be brought Low. However once the write operation started, CS may be either
High or Low. But in the case of connecting the WC pin to the CS pin. CS and WC must be brought Low during
programming cycle.(If the WC pin is brought High during the write cycle, the write operation is halted. In that case, the
data of the specified address is not guaranteed. It is necessary to rewrite it.)
2) After the R / B pin changed Busy to Ready, once CS is brought High, then CS keep Low ,which means the status of
being able to accept an instruction. The device can take in the input from SK and DI, but in the case of keeping CS
Low without being brought High once, the input is canceled until being CS High once.
3) At the rising edge of 32 nd clock, the R / B pin will be driven Low after the specified time delay (tSV).
4) During programming, R / B is tied to Low by the device (On the rising edge of SK taken in the last data (D15), internal
timer starts and automatically finished after the data of memory cell is written spending tE / W. SK could be either High
or Low at the time.
5) After input write instruction, also the DO pin will be able to show the status of R / B, in the case that CS is falling from
High to Low while SK is tied to Low. (Refer to READY / BUSY STATUS in the next page.)
(5) READY / BUSY STATUS (on the R / B pin, the DO pin)
1)The DO pin outputs the READY / BUSY status of the internal part, which shows whether the device is ready to receive
the next instruction or not. (High or Low)
After the write instruction is completed, if CS is brought from high to low while SK is Low, the DO pin outputs the
internal status. (The R / B pin may be no connection.
2) When written to the memory cell, R / B status is output after tSV spent from the rising edge of 32 th clock on SK.
R / B =Low : under writing
After spending tE / W operating the internal timer, the device automatically finishes writing.
During tE / W, the memory array is accessed and any instruction is not received.
R / B=High : ready
Auto programming has been completed. The device is ready to receive the next Instruction.
Fig.9 R / B Status Output Timing
SK
CS
DI
DO
READY
READY
READY
BUSY
t
PD
t
OH
BUSY
WRITE INSTRUCTION
CLOCK
R / B
HIGH-Z
HIGH-Z