AT21CS01 datasheet(26/47 Pages) MICROCHIP

26 / 47 page

To determine if the device is already set to Standard Speed mode, the device address byte with the

opcode of 1101b (Dh) must be sent to the device, along with the appropriate slave address combination

and the Read/Write bit set to a logic ‘1’. The device will return an ACK (logic ‘0’) if it was set for Standard

Speed mode. It will return a NACK (logic ‘1’) if the device was not currently set for Standard Speed mode.

Note: The AT21CS11 will NACK this command.

6.6.2

High-Speed Mode

The device can be set to High-Speed mode or checked to see whether or not it is in High-Speed mode

with the use of the Eh opcode. This transaction only requires eight bits. The power-on default for the

AT21CS01/11 is High-Speed mode.

To set the device to High-Speed mode, the master must send a Start condition, followed by the device

address byte with the opcode of 1110b (Eh) specified, along the appropriate slave address combination

and the Read/Write bit set to a logic ‘0’. The device will return an ACK (Logic 0) and will be immediately

ready to receive commands for high-speed operation.

To determine if the device is already set to High-Speed mode, the device address byte with the opcode of

1110b (Eh) specified must be sent to the device along with the appropriate slave address combination

and the Read/Write bit set to a logic ‘1’. The device will return an ACK (logic ‘0’) if it was set for High-

Speed mode. It will return a NACK (logic ‘1’) if the device was not currently set for High-Speed mode.

Note: The AT21CS11 will ACK this command.

AT21CS01/AT21CS11

Datasheet

DS20005857A-page 26

AT21CS01 Datasheet(PDF) 26 Page - Microchip Technology