18

1937J–DFLSH–9/05

AT45DB021B

11. Read Operations

The following block diagram and waveforms illustrate the various read sequences available.

11.1

Main Memory Page Read

11.2

Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)

11.3

Buffer Read

FLASH MEMORY ARRAY

PAGE (264 BYTES)

BUFFER 2 (264 BYTES)

BUFFER 1 (264 BYTES)

I/O INTERFACE

MAIN MEMORY

PAGE TO

BUFFER 1

MAIN MEMORY

PAGE TO

BUFFER 2

MAIN MEMORY

PAGE READ

BUFFER 1

READ

BUFFER 2

READ

SO

SI

CMD

rrrr r, PA9-7

PA6-0, BA8

BA7-0

X

XXX

CS

n

n+1

SO

SI

CMD

rrrr r, PA9-7

PA6-0, X

X

Starts reading page data into buffer

CS

SO

SI

CMD

X

X···X, BFA8

BFA7-0

CS

n

n+1

SO

X

Each transition represents

8 bits and 8 clock cycles

n = 1st byte read

n+1 = 2nd byte read