LE25LB643

No.NA1342-11/14

5. Write (WRITE)

The LE25LB643 enables pages with up to 32bytes to be written. Any number of bytes from 1 to 32bytes can be written

within the same sector page (page addresses : A15 to A5). “Figure 9 Write” shows the write timing waveforms, and

Figure 12 shows a write flowchart. After the falling CS edge, the command (02H) is input followed by the 16-bit

addresses (Add). The write data is then loaded until the rising CS edge, and the internal addresses (A4 to A0) are

incremented (Add+1) every time the data is loaded in 1-byte increments. The data loading continues until the rising CS

edge. If the data loaded has exceeded 32bytes, the 32bytes loaded last are written. The write data must be loaded in

1-byte increments, and the write operation is not performed at the rising CS edge occurring at any other timing. The

write time is 10ms (max.) when 32bytes (1page) are written at one time.

Figure 9 Write

• Addresses A15 - A13 are “don’t care.”

6. Hold Function

Using HOLD pin, the hold function suspends serial communication (it places it in the hold status). “Figure 10 HOLD”

shows the timing waveforms. The device is placed in the hold status at the falling HOLD edge while the logic level of

SCK is low, and it exits from the hold status at the rising HOLD edge. When the logic level of SCK is high, HOLD must

not rise or fall. The hold function takes effect when the logic of CS is low, and the hold status is exited and serial

communication is reset at the rising CS edge. In the hold status, the SO output is in the high-impedance state, and SI

and SCK are “don’t care.”

Figure 10 HOLD

CS

HOLD

SCK

SO

Active

Active

HOLD

tHS

tHS

tHH

tHLZ

tHH

tHHZ

High Impedance

CS

SCK

SI

SO

8CLK

High Impedance

Mode3

Mode0

0123

456

78

15 16

23 24

31 32

39 40

47

279

Self-timed

Write Cycle

tWC

02h

Add.

Add.

PD

PD

PD

PD

(00000010)

(A15-A8)

(A7-A0)

(N)

(N+1)

(N+2)

(N+31)