LE25FU406B

No.A1066-8/22

2. Status Registers

The status registers hold the operating and setting statuses inside the device, and this information can be read (status

register read) and the protect information can be rewritten (status register write). There are 8 bits in total, and "Table 3

Status registers" gives the significance of each bit.

Table 3 Status Registers

Bit

Name

Logic

Function

Power-on Time Information

0

Ready

Bit0

RDY

1

Erase/Program

0

0

Write disabled

Bit1

WEN

1

Write enabled

0

0

Bit2

BP0

1

Nonvolatile information

0

Bit3

BP1

1

Nonvolatile information

0

Bit4

BP2

1

Block protect information

See status register descriptions on BP0, BP1, and BP2.

Nonvolatile information

Bit5

0

Bit6

Reserved bits

0

0

Status register write enabled

Bit7

SRWP

1

Status register write disabled

Nonvolatile information

2-1. Status register read

The contents of the status registers can be read using the status register read command. This command can be executed

even during the following operations.

• Small sector erase, sector erase, chip erase

• Page program

• Status register write

"Figure 6 Status Register Read" shows the timing waveforms of status register read. Consisting only of the first bus

cycle, the status register command outputs the contents of the status registers synchronized to the falling edge of the

clock (SCK) with which the eighth bit of (05h) has been input. In terms of the output sequence, SRWP (bit 7) is the first

to be output, and each time one clock is input, all the other bits up to RDY (bit 0) are output in sequence, synchronized

to the falling clock edge. If the clock input is continued after RDY (bit 0) has been output, the data is output by

returning to the bit (SRWP) that was first output, after which the output is repeated for as long as the clock input is

continued. The data can be read by the status register read command at any time (even during a program or erase cycle).

Figure 6 Status Register Read

CS

SCK

SI

SO

MSB

MSB

MSB

05h

DATA

DATA

High Impedance

8

3

2

1

0

7

6

5

4

15

23

Mode 3

Mode 0

8CLK

16

DATA