M29W640FB STMICROELECTRONICS [STMicroelectronics], M29W640FB Datasheet - Page 57

• Manufacturer Part Number: M29W640FB
• Description: 64 Mbit (8Mb x8 or 4Mb x16, Page, Boot Block) 3V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M29W640FT, M29W640FB
Appendix B Common Flash Interface (CFI)
Table 22.
1. Query data are always presented on the lowest order data outputs.
1Bh
x16
10h
27h
40h
61h
Address
The Common Flash Interface is a JEDEC approved, standardized data structure that can be
read from the Flash memory device. It allows a system software to query the device to
determine various electrical and timing parameters, density information and functions
supported by the memory. The system can interface easily with the device, enabling the
software to upgrade itself when necessary.
When the CFI Query Command is issued the device enters CFI Query mode and the data
structure is read from the memory. Tables 22, 23, 24, 25, 26, and 27, show the addresses used
to retrieve the data.
The CFI data structure also contains a security area where a 64 bit unique security number is
written (see
the final user. It is impossible to change the security number after it has been written by ST.
Query Structure Overview
4Eh
C2h
20h
36h
80h
x8
Table 27: Security Code
CFI Query Identification String
System Interface Information
Device Geometry Definition
Primary Algorithm-specific Extended
Query table
Security Code Area
Sub-section Name
Area). This area can be accessed only in Read mode by
Command set ID and algorithm data offset
Device timing & voltage information
Flash device layout
Additional information specific to the Primary
Algorithm (optional)
64 bit unique device number
Description
9 Part Numbering
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