at45db021a ATMEL Corporation, at45db021a Datasheet - Page 14

• Manufacturer Part Number: at45db021a
• Description: 2-megabit 2.7-volt Only Serial Dataflash
• Manufacturer: ATMEL Corporation

Write Operations
The following block diagram and waveforms illustrate the various write sequences available.
Main Memory Page Program through Buffers
Buffer Write
Buffer to Main Memory Page Program (Data from Buffer Programmed into Flash Page)
14
Each transition represents
8 bits and 8 clock cycles
CS
SI
CS
SI
AT45DB021A
PAGE PROGRAM
MAIN MEMORY
PAGE (264 BYTES)
BUFFER 1 (264 BYTES)
CMD
BUFFER 1 TO
BUFFER 1
CMD
CS
WRITE
SI
r r r r r, PA9-7
X
PA6-0, BFA8
CMD
X···X, BFA8
FLASH MEMORY ARRAY
MAIN MEMORY PAGE
PROGRAM THROUGH
BUFFER 1
r r r r r, PA9-7
I/O INTERFACE
THROUGH BUFFER 2
BFA7-0
BFA7-0
PAGE PROGRAM
MAIN MEMORY
SI
Starts self-timed erase/program operation
PA6-0, X
n
n
BUFFER 2 (264 BYTES)
n+1
· Completes writing into selected buffer
X
n+1
· Completes writing into selected buffer
· Starts self-timed erase/program operation
BUFFER 2 TO
MAIN MEMORY
PAGE PROGRAM
BUFFER 2
WRITE
Last Byte
n = 1st byte read
n+1 = 2nd byte read
Last Byte