M28W320 STMicroelectronics, M28W320 Datasheet - Page 16

• Manufacturer Part Number: M28W320
• Description: 32 Mbit 2Mb x16/ Boot Block Low Voltage Flash Memory
• Manufacturer: STMicroelectronics

M28W320CT, M28W320CB
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.
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
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’.
16/42
Offset
02h-0Fh
1Bh
00h
10h
27h
Offset
P
A
00h
01h
10h
11h
12h
13h
14h
15h
16h
17h
18h
19h
1Ah
detailed in Tables 15, 16, 17, 18 and 19. Query data are always presented on the lowest order data outputs.
Reserved
CFI Query Identification String
System Interface Information
Device Geometry Definition
Primary Algorithm-specific Extended Query table
Alternate Algorithm-specific Extended Query table
offset = P = 0035h
value = A = 0000h
88BBh - bottom
88BAh - top
reserved
0020h
0051h
0052h
0059h
0003h
0000h
0000h
0000h
0000h
0000h
Data
Sub-section Name
Manufacturer Code
Device Code
Reserved
Query Unique ASCII String ”QRY”
Query Unique ASCII String ”QRY”
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
Alternate Vendor Command Set and Control Interface ID Code second vendor
- specified algorithm supported (note: 0000h means none exists)
Address for Alternate Algorithm extended Query table
note: 0000h means none exists
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.
Reserved for algorithm-specific information
Command set ID and algorithm data offset
Device timing & voltage information
Flash device layout
Additional information specific to the Primary
Algorithm (optional)
Additional information specific to the Alternate
Algorithm (optional)
Description
Description