9

AT45DB011B

1984J–DFLASH–06/06

Operation Mode

Summary

The modes described can be separated into two groups – modes which make use of the Flash

memory array (Group A) and modes which do not make use of the Flash memory array

(Group B).

Group A modes consist of:

1.

Main Memory Page Read

2.

Main Memory Page to Buffer Transfer

3.

Main Memory Page to Buffer Compare

4.

Buffer to Main Memory Page Program with Built-in Erase

5.

Buffer to Main Memory Page Program without Built-in Erase

6.

Page Erase

7.

Block Erase

8.

Main Memory Page Program through Buffer

9.

Auto Page Rewrite

Group B modes consist of:

1.

Buffer Read

2.

Buffer Write

3.

Status Register Read

If a Group A mode is in progress (not fully completed), then another mode in Group A should

not be started. However, during this time in which a Group A mode is in progress (other than

Main Memory Page Read), Status Register Read from Group B can be started. Furthermore,

during Page Erase and Block Erase operation in progress from Group A, any of the modes

from Group B can be started.

Pin Descriptions

SERIAL INPUT (SI): The SI pin is an input-only pin and is used to shift data into the device.

The SI pin is used for all data input, including opcodes and address sequences.

SERIAL OUTPUT (SO): The SO pin is an output-only pin and is used to shift data out from the

device.

SERIAL CLOCK (SCK): The SCK pin is an input-only pin and is used to control the flow of

data to and from the DataFlash. Data is always clocked into the device on the rising edge of

SCK and clocked out of the device on the falling edge of SCK.

CHIP SELECT (CS): The DataFlash is selected when the CS pin is low. When the device is

not selected, data will not be accepted on the SI pin, and the SO pin will remain in a high-

impedance state. A high-to-low transition on the CS pin is required to start an operation, and a

low-to-high transition on the CS pin is required to end an operation.

WRITE PROTECT: If the WP pin is held low, the first 256 pages of the main memory cannot

be reprogrammed. The only way to reprogram the first 256 pages is to first drive the protect

pin high and then use the program commands previously mentioned. If this pin and feature are

not utilized it is recommended that the WP pin be driven high externally.