LE25S40FD

www.onsemi.com

11

6. Small Sector Erase

Small sector erase is an operation that sets the memory cell data in any small sector to "1". A small sector consists of

4Kbytes. "Figure 11 Small Sector Erase" shows the timing waveforms, and Figure 20 shows a small sector erase

flowchart. The small sector erase command consists of the first through fourth bus cycles, and it is initiated by

inputting the 24-bit addresses following (20h) or (D7h). Addresses A18 to A12 are valid, and Addresses A23 to A19

are "don't care". After the command has been input, the internal erase operation starts from the rising CS edge, and it

ends automatically by the control exercised by the internal timer. Erase end can also be detected using status register

RDY.

Figure 11 Small Sector Erase

7. Sector Erase

Sector erase is an operation that sets the memory cell data in any sector to "1". A sector consists of 64Kbytes.

"Figure 12 Sector Erase" shows the timing waveforms, and Figure 20 shows a sector erase flowchart. The sector

erase command consists of the first through fourth bus cycles, and it is initiated by inputting the 24-bit addresses

following (D8h). Addresses A18 to A16 are valid, and Addresses A23 to A19 are "don't care". After the command

has been input, the internal erase operation starts from the rising CS edge, and it ends automatically by the control

exercised by the internal timer. Erase end can also be detected using status register RDY.

Figure 12 Sector Erase

Self-timed

Erase Cycle

SCK

SI

High Impedance

SO

CS

tSSE

Add.

20h / D7h

Add.

Add.

15

0

1

2

3

4

5

6

7

8

23

16

24

31

Mode3

Mode0

8CLK

MSB

SCK

SI

High Impedance

SO

CS

tSE

Self-timed

Erase Cycle

Add.

D8h

Add.

Add.

15

0

1

2

3

4

5

6

7

8

23

16

24

31

Mode3

Mode0

8CLK

MSB