m29w400f Numonyx, m29w400f Datasheet - Page 43

• Manufacturer Part Number: m29w400f
• Description: 8-mbit 1 Mbit?8 / 512 Kbit?16 ; 4-mbit 512 Kbit?8 / 256 Kbit?16 Boot Block 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 CFI Query command is issued the device enters CFI query mode and the data
structure is read from the memory.
Table 28
The CFI data structure also contains a security area where a 64-bit unique security number
is written (see
by the final user. It is impossible to change the security number after it has been written by
Numonyx. Issue a Read command to return to read mode.
Table 23.
1. Query data are always presented on the lowest order data outputs.
x 16
1Bh
10h
27h
40h
61h
Address
show the addresses used to retrieve the data.
C2h
20h
36h
4Eh
80h
x 8
Common Flash interface (CFI)
Query structure overview
Table 28: Security code
CFI query identification string
System interface information
Device geometry definition
Primary algorithm-specific extended
query table
Security code area
Sub-section name
Table
area). This area can be accessed only in read mode
(1)
23,
Table
24,
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
25,
Table
Description
26,
Table 27
and
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