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AT25010/020/040

0606M–SEEPR–06/03

SPI Serial Interface

Functional

Description

The AT25010/020/040 is designed to interface directly with the synchronous serial

peripheral interface (SPI) of the 6805 and 68HC11 series of microcontrollers.

The AT25010/020/040 utilizes an 8-bit instruction register. The list of instructions and

their operation codes are contained in Table 1. All instructions, addresses, and data are

transferred with the MSB first and start with a high-to-low CS transition.

Note:

“A” represents MSB address bit A8.

Table 1. Instruction Set for the AT25010/020/040

Instruction Name

Instruction Format

Operation

WREN

0000 X110

Set Write Enable Latch

WRDI

0000 X100

Reset Write Enable Latch

RDSR

0000 X101

Read Status Register

WRSR

0000 X001

Write Status Register

READ

0000 A011

Read Data from Memory Array

WRITE

0000 A010

Write Data to Memory Array