at45db021b ATMEL Corporation, at45db021b Datasheet - Page 18

• Manufacturer Part Number: at45db021b
• Description: At45db021b 2-megabit 2.7-volt Only Dataflash
• Manufacturer: ATMEL Corporation

11. Read Operations
11.1
11.2
11.3
18
Each transition represents
CS
SO
SI
8 bits and 8 clock cycles
Main Memory Page Read
Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)
Buffer Read
AT45DB021B
CMD
SO
CS
SI
The following block diagram and waveforms illustrate the various read sequences available.
r r r r r, PA9-7
SO
CS
SI
CMD
MAIN MEMORY
PA6-0, BA8
PAGE (264 BYTES)
BUFFER 1 (264 BYTES)
BUFFER 1
BUFFER 1
PAGE TO
READ
CMD
X
BA7-0
X···X, BFA8
r r r r r, PA9-7
X
FLASH MEMORY ARRAY
Starts reading page data into buffer
BFA7-0
PA6-0, X
I/O INTERFACE
X
SO
X
MAIN MEMORY
PAGE READ
X
X
n
BUFFER 2 (264 BYTES)
n+1
X
n = 1st byte read
n+1 = 2nd byte read
MAIN MEMORY
PAGE TO
BUFFER 2
BUFFER 2
READ
n
1937J–DFLSH–9/05
n+1