AT21CS01 datasheet(21/47 Pages) MICROCHIP

21 / 47 page

5.5

Freeze ROM Zone State (Opcode 1h)

The opcode 1h is used to permanently freeze the current state of the ROM Zone registers. Once set, the

ROM Zone registers are read-only.

Therefore, any zone that is not already read-only cannot be subsequently converted to ROM. Refer to

Freeze ROM Zone Registers for additional details.

5.6

Manufacturer ID Read (Opcode Ch)

Manufacturer identification, device density, and device revision information can be read from the device

using the opcode Ch. The full details of the format of the data returned by this command are found in

Manufacturer ID Read.

5.7

Standard Speed Mode (Opcode Dh)

The AT21CS01 can be set to Standard Speed mode or checked to see whether or not it is in Standard

Speed mode with the use of the Dh opcode. Further details are covered in Standard Speed Mode

(AT21CS01). The AT21CS11 does not offer Standard Speed mode and therefore will NACK this

command.

5.8

High-Speed Mode (Opcode Eh)

The AT21CS01 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. The AT21CS11 only operates in High-Speed mode and therefore

will ACK this command. Further details are covered in High-Speed Mode.

AT21CS01/AT21CS11

Datasheet

DS20005857A-page 21

AT21CS01 数据表(PDF) 21 Page - Microchip Technology