LE25FW808

No.A0839-13/27

4-2. Status Register Write

By Status Register Write, BP0, BP1, BP2 and SRWP can be rewritten. RDY, WEN, Bit5, and Bit6 are read-only, BP0,

BP1, BP2 and SRWP are non-volatile.

A timing waveform is shown in Figure 10 and a flow chart is shown in Figure 23.

Status Register Write command consists of the 1st bus cycle and the 2nd bus cycle, and internal Write operation starts

with the rising edge of CS after inputting data after OP-code (01h). Erase and program are automatically performed

inside the device and a Status Register Write rewrites BP0, BP1, BP2 and SRWP non-volatilized data. The write-in data

to read-only bits (RDY, WEN, Bit 5, Bit 6) are don't care.

The end of a Status Register Write is detectable with RDY of a Status Register Read.

The number of times of rewriting of a Status Register Write is 1,000 times (min).

In order to perform a Status Register Write, it is necessary to change WEN of a Status Register into "1" state for WP pin.

Figure 10 Status Register Write

4-3. Contents of Each Status Register

RDY (bit 0)

The RDY register is for detecting the write (program, erase and status register write) end. When it is "1", the device is

in a busy state, and when it is "0", it means that write is completed.

tSRW

Self-timed

Write Cycle

SCK

SI

High Impedance

SO

CS

DATA

01h

15

0

1

2

3

4

5

6

7

8

Mode3

Mode0

8CLK

WP

tWPH

tWPS