M28W320CT, M28W320CB

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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 14, 15, 16, 17, 18 and 19 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 14,

15, 16 and 17 show the addresses used to retrieve

each data. The CFI data structure contains also a

security area; in this section, a 64 bit unique secu-

rity 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 return to

Read mode. Refer to the CFI Query instruction to

understand how the M28W320C enters the CFI

Query mode.

Table 14. 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 15, 16, 17, 18 and 19. Query data are always presented on the lowest order data outputs.

Table 15. CFI Query Identification String

Note: 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

88BAh - top

88BBh - 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

0003h

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

defining a specific algorithm

14h

0000h

15h

offset = P = 0035h

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