45DB041B Datasheet, PDF (17/33 Pages) ATMEL Corporation – 4-megabit 2.5-volt Only or 2.7-volt Only DataFlash

AT45DB041B
Read Operations
The following block diagram and waveforms illustrate the various read sequences
available.
FLASH MEMORY ARRAY
PAGE (264 BYTES)
MAIN MEMORY
PAGE TO
BUFFER 1
BUFFER 1 (264 BYTES)
BUFFER 1
READ
MAIN MEMORY
PAGE TO
BUFFER 2
BUFFER 2 (264 BYTES)
MAIN MEMORY
PAGE READ
BUFFER 2
READ
I/O INTERFACE
SO
Main Memory Page Read
CS
SI
CMD
r r r r, PA10-7 PA6-0, BA8
BA7-0
X
X
X
X
SO
n
n+1
Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)
Starts reading page data into buffer
CS
SI
CMD
r r r r, PA10-7 PA6-0, X
X
SO
Buffer Read
CS
SI
SO
CMD
X
X···X, BFA8 BFA7-0
X
n
n+1
Each transition represents
8 bits and 8 clock cycles
n = 1st byte read
n+1 = 2nd byte read
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1938F–DFLSH–10/02