LE25S81A datasheet(7/51 Pages) ONSEMI

7 / 51 page

LE25S81A

www.onsemi.com

Device Operation

7-1. Standard SPI Modes

The read, erase, program and other required functions of the device are executed through the command registers. The

serial I/O corrugate is shown in "Figure 1. SPI Modes" and the command list are shown in "Table.1-1. Command Settings

(Standard SPI)". At the falling CS edge the device is selected, and serial input is enabled for the commands, addresses, etc.

These inputs are normalized in 8 bit units and taken into the device interior in synchronization with the rising edge of SCK,

which causes the device to execute operation according to the command that is input.

The LE25S81A supports both serial interface SPI mode 0 and SPI mode 3. At the falling CS edge, SPI mode 0 is

automatically selected if the logic level of SCK is low, and SPI mode 3 is automatically selected if the logic level of SCK

is high.

Figure 1. SPI Modes

7-2. Dual SPI Modes

The LE25S81A supports Dual SPI operations when using "Dual Output Read (RDDO: 3Bh)", "Dual I/O Read (RDIO:

BBh)". The SI and SO pins change into the input/output pin (SIOx) during the Dual SPI modes. The command list is

shown in "Table.1-2. Command Settings (Dual SPI)".

Pin Configurations at Dual SPI Mode

Standard SPI

Dual SPI



SIO0



SIO1

SCK

High Impedance

DATA

1st byte

2nd byte

8CLK

Mode0

Mode3

Nth byte

MSB

(Bit7)

LSB

(Bit0)

LE25S81A Datasheet(PDF) 7 Page - ON Semiconductor