at49bv642dt ATMEL Corporation, at49bv642dt Datasheet - Page 7

• Manufacturer Part Number: at49bv642dt
• Description: 64-megabit 4m X 16 3-volt Only Flash Memory
• Manufacturer: ATMEL Corporation

3.11
3.12
3.13
3.14
3631A–FLASH–04/06
Common Flash Interface (CFI)
Hardware Data Protection
Input Levels
Output Levels
Common Flash Interface (CFI) is a published, standardized data structure that may be read from
a Flash device. CFI allows system software to query the installed device to determine the config-
urations, various electrical and timing parameters, and functions supported by the device. CFI is
used to allow the system to learn how to interface to the Flash device most optimally. The two
primary benefits of using CFI are ease of upgrading and second source availability. The com-
mand to enter the CFI Query mode is a one-bus cycle command which requires writing data 98h
to address 55h. The CFI Query command can be written when the device is ready to read data
or can also be written when the part is in the product ID mode. Once in the CFI Query mode, the
system can read CFI data at the addresses given in the
Table” on page
Hardware features protect against inadvertent programs to the AT49BV642D(T) in the following
ways: (a) V
power-on delay: once V
out 10 ms (typical) before programming. (c) Program inhibit: holding any one of OE low, CE high
or WE high inhibits program cycles. (d) V
While operating with a 2.65V to 3.6V power supply, the address inputs and control inputs (OE,
CE and WE) may be driven from 0 to 5.5V without adversely affecting the operation of the
device. The I/O lines can be driven from 0 to V
For the AT49BV642D(T), output high levels are equal to V
3.6V output levels, V
CC
sense: if V
24. To exit the CFI Query mode, the product ID exit command must be given.
CCQ
CC
must be tied to V
CC
has reached the V
is below 1.8V (typical), the program function is inhibited. (b) V
PP
CC
is less than V
.
CC
CCQ
sense level, the device will automatically time-
+ 0.6V.
ILPP
“Common Flash Interface Definition
.
CCQ
- 0.1V (not V
AT49BV642D(T)
CC
). For 2.65V to
CC
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