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M36D232A, M36DR232B

COMMON FLASH INTERFACE (CFI)

The Common Flash Interface (CFI) specification is

a JEDEC approved, standardised data structure

that can be read from the Flash memory device.

CFI allows a system software to query the flash

device to determine various electrical and timing

parameters, density information and functions

supported by the device. CFI allows the system to

easily interface to the Flash memory, to learn

about its features and parameters, enabling the

software to configure itself when necessary.

Tables 18, 19, 20, and 21 show the address used

to retrieve each data.

The CFI data structure gives information on the

device, such as the sectorization, the command

set and some electrical specifications. Tables 18,

19, 20, and 21 show the addresses used to re-

trieve each data. The CFI data structure contains

also a security area; in this section, a 64 bit unique

security number is written, starting at address 81h.

This area can be accessed only in read mode and

there are no ways of changing the code after it has

been written by ST. Write a read instruction to re-

turn to Read mode. Refer to the CFI Query instruc-

tion to understand how the M36DR232 enters the

CFI Query mode.

Table 18. Query Structure Overview

Note: The Flash memory display the CFI data structure when CFI Query command is issued. In this table are listed the main sub-sections

detailed in Tables 19, 20 and 21. Query data are always presented on the lowest order data outputs.

Table 19. CFI Query Identification String

Note: 1. Query data are always presented on the lowest - order data outputs (DQ7-DQ0) only. DQ8-DQ15 are ‘0’.

Offset

Sub-section Name

Description

00h

Reserved

Reserved for algorithm-specific information

10h

CFI Query Identification String

Command set ID and algorithm data offset

1Bh

System Interface Information

Device timing & voltage information

27h

Device Geometry Definition

Flash device layout

P

Primary Algorithm-specific Extended Query table

Additional information specific to the Primary

Algorithm (optional)

A

Alternate Algorithm-specific Extended Query table

Additional information specific to the Alternate

Algorithm (optional)

Offset

Data

Description

00h

0020h

Manufacturer Code

01h

00A0h - top

00A1h - bottom

Device Code

02h-0Fh

reserved

Reserved

10h

0051h

Query Unique ASCII String "QRY"

11h

0052h

Query Unique ASCII String "QRY"

12h

0059h

Query Unique ASCII String "QRY"

13h

0002h

Primary Algorithm Command Set and Control Interface ID code 16 bit ID code

defining a specific algorithm

14h

0000h

15h

offset = P = 0040h

Address for Primary Algorithm extended Query table

16h

0000h

17h

0000h

Alternate Vendor Command Set and Control Interface ID Code second vendor

- specified algorithm supported (note: 0000h means none exists)

18h

0000h

19h

value = A = 0000h

Address for Alternate Algorithm extended Query table

note: 0000h means none exists

1Ah

0000h