m29dw256g Numonyx, m29dw256g Datasheet - Page 74

• Manufacturer Part Number: m29dw256g
• Description: 256-mbit X16, Multiple Bank, Page, Dual Boot 3 V Supply Flash Memory
• Manufacturer: Numonyx

Appendix B
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 Read CFI Query command is issued, the memory enters read CFI query mode and read
operations output the CFI data.
addresses (A0-A7) used to retrieve the data. The CFI data structure also contains a security area where
a 64-bit unique security number is written (see
only in read mode by the final user. It is impossible to change the security number after it has been
written by Numonyx.
Table 35.
1. Query data are always presented on the lowest order data outputs.
Table 36.
1. Query data are always presented on the lowest order data outputs (DQ7-DQ0) only. DQ8-DQ15 are ‘0’.
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Address
Address
1Ah
x16
10h
12h
13h
14h
15h
16h
17h
18h
19h
11h
x16
10h
1Bh
27h
40h
61h
Query structure overview
CFI query identification string
CFI query identification string
System interface information
Device geometry definition
Primary algorithm-specific extended query table
Security code area
0051h
0052h
0059h
0002h
0000h
0040h
0000h
0000h
0000h
0000h
0000h
Data
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
Alternate vendor command set and control interface ID code second
vendor - specified algorithm supported
Address for alternate algorithm extended query table
Common flash interface (CFI)
Sub-section name
Table
35,
(1)
Table
(1)
Table 40: Security code
36,
Description
Table
37,
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
Table
38,
area). This area can be accessed
Table 39
Table
Description
39)
and
Table 40
compatible
Spansion
P = 40h
Value
show the
NA
NA
‘Q’
‘R’
‘Y’