LE25LB642CT

2. Status Registers

The status registers read the operating and setting statuses inside the device from outside (status register read) and set

the protect information (status register write). There are 8 bits in total, and “Table 2 Status Registers” gives the

significance of each bit.

Table 2 Status Registers

Bit

Name

Logic

Function

Power-on time

Information

0

Ready

Bit0

RDY

1

Busy (in write operation)

0

0

Write disabled

Bit1

WEN

1

Write enabled

0

0

Bit2

BP0

1

Nonvolatile

information

0

Bit3

BP1

1

Block protect information

See status register description on BP0 and BP1

Nonvolatile

information

Bit4

×

0

Reserved bit

0

Bit5

×

0

Reserved bit

0

Bit6

×

0

Reserved bit

0

0

Status register write enabled

Bit7

SRWP

1

Status register write disabled

Nonvolatile

information

No.NA1471-8/14

2-1. Status Register Read (RDSR)

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

even during write operation.

“Figure 5 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 (bit7) is the first

to be output, and each time one clock is input, all the other bits up to RDY (bit0) are output in sequence, synchronized

to the falling clock edge. If the clock input is continued after RDY (bit0) has been output, the data is output by returning

to the bit (SRWP) that was first output, after which the output is repeated as long as the clock input is continued. The

data can be read by the status register read command at any time.

Figure 5 Status Register Read

CS

SCK

SI

SO

0

Mode3

8CLK

Hight Impedance

Status Register Out

7 6

5 4 3

2107

05h

Mode0

12345

6 78

9 10 11 12 13 14 15

(00000101)