M29F800DB STMICROELECTRONICS [STMicroelectronics], M29F800DB Datasheet - Page 29

• Manufacturer Part Number: M29F800DB
• Description: 8 Mbit (1Mb x8 or 512Kb x16, Boot Block) 5V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

APPENDIX B. COMMON FLASH INTERFACE (CFI)
The Common Flash Interface is a JEDEC ap-
proved, 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 mem-
ory. The system can interface easily with the de-
vice, enabling the software to upgrade itself when
necessary.
When the CFI Query Command is issued the de-
vice enters CFI Query mode and the data structure
Table 21. Query Structure Overview
Note: Query data are always presented on the lowest order data outputs.
Table 22. CFI Query Identification String
Note: Query data are always presented on the lowest order data outputs (DQ7-DQ0) only. DQ8-DQ15 are ‘0’.
1Ah
x16
10h
11h
12h
13h
14h
15h
16h
17h
18h
19h
1Bh
x16
10h
27h
40h
61h
Address
Address
2Ah
2Ch
2Eh
20h
22h
24h
26h
28h
30h
32h
34h
x8
4Eh
C2h
20h
36h
80h
x8
0051h
0052h
0059h
0002h
0000h
0040h
0000h
0000h
0000h
0000h
0000h
Data
CFI Query Identification String
System Interface Information
Device Geometry Definition
Primary Algorithm-specific Extended
Query table
Security Code Area
Query Unique ASCII String "QRY"
Primary Algorithm Command Set and Control Interface ID code 16 bit
ID code defining a specific algorithm
Address for Primary Algorithm extended Query table (see Table 24)
Alternate Vendor Command Set and Control Interface ID Code second
vendor - specified algorithm supported
Address for Alternate Algorithm extended Query table
Sub-section Name
is read from the memory. Tables 21, 22, 23, 24, 25
and 25 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 writ-
ten (see Table , Security Code area). This area
can be accessed only in Read mode by the final
user. It is impossible to change the security num-
ber after it has been written by ST. Issue a Read
command to return to Read mode.
Description
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
M29F800DT, M29F800DB
Description
Compatible
P = 40h
Value
AMD
"Q"
"R"
"Y"
NA
NA
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