Manual

17
AT45DB321B
2223D–DFLASH–10/02
Read Operations The following block diagram and waveforms illustrate the various read sequences
available.
Main Memory Page Read
Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)
Buffer Read
FLASH MEMORY ARRAY
PAGE (528 BYTES)
BUFFER 2 (528 BYTES)BUFFER 1 (528 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
PA5-0, BA9-8
BA7-0 X
XXX
CS
n n+1
SO
r , PA12-6
SI
CMD
PA5-0, XX X
Starts reading page data into buffer
CS
SO
r , PA12-6
SI
CMD
X
X···X, BFA9-8
BFA7-0
CS
n n+1
SO
X
E
ach transition represents
8 bits and 8 clock cycles
n = 1st byte read
n+1 = 2nd byte read