Rainbow Electronics AT45DB321B - Manual (Page 17)

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 X X X
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
Each transition represents
8 bits and 8 clock cycles
n = 1st byte read
n+1 = 2nd byte read