m29dw640f Numonyx, m29dw640f Datasheet - Page 21

• Manufacturer Part Number: m29dw640f
• Description: 64 Mbit 8mb X8 Or 4mb X16, Multiple Bank, Page, Boot Block 3v Supply Flash Memory
• Manufacturer: Numonyx

M29DW640F
4
4.1
4.1.1
4.1.2
Command interface
All Bus Write operations to the memory are interpreted by the Command Interface.
Commands consist of one or more sequential Bus Write operations. Failure to observe a
valid sequence of Bus Write operations will result in the memory returning to Read mode.
The long command sequences are imposed to maximize data security.
The address used for the commands changes depending on whether the memory is in 16-
bit or 8-bit mode. See either
used, for a summary of the commands.
Standard commands
Read/Reset command
The Read/Reset command returns the memory to its Read mode. It also resets the errors in
the Status Register. Either one or three Bus Write operations can be used to issue the
Read/Reset command.
The Read/Reset command can be issued, between Bus Write cycles before the start of a
program or erase operation, to return the device to read mode. If the Read/Reset command
is issued during the timeout of a Block erase operation then the memory will take up to 10µs
to abort. During the abort period no valid data can be read from the memory. The
Read/Reset command will not abort an Erase operation when issued while in Erase
Suspend.
Auto Select command
The Auto Select command is used to read the Manufacturer Code and Device Code, the
Block Protection Status and the Extended Block Indicator. It can be addressed to either
Bank. Three consecutive Bus Write operations are required to issue the Auto Select
command. The final Write cycle must be addressed to one of the Banks. Once the Auto
Select command is issued Bus Read operations to the Bank where the command was
issued output the Auto Select data. Bus Read operations to the other Bank will output the
contents of the memory array. The memory remains in Auto Select mode until a Read/Reset
or CFI Query command is issued. This command must be issued addressing the same
Bank, as was given when entering Auto Select Mode.
In Auto Select mode the Manufacturer Code can be read using a read operation, A6 and A3
to A0 each held at V
be set to either V
The Device Codes can be read using a read operation, A6 held at V
the levels given in
address bits may be set to either V
The Block Protection Status of each block can be read using a read operation, A6 A3 A2 A0
each held at V
specifying the address of the block inside the Bank. The other address bits may be set to
either V
Inputs/Outputs DQ0-DQ7, otherwise 00h is output.
IL
or V
IH
IL
. If the addressed block is protected then 01h is output on Data
, A1 held at V
IL
Table 4
or V
IL
, and A21-A19 set to the Bank Address. The other address bits may
IH
.
and
Table 6
IH
Table 5
, and A21-A19 set to the Bank Address, and A18-A12
IL
, or
or V
, and A21-A19 set to the Bank Address. The other
Table 7
IH
.
, depending on the configuration that is being
IL
, A3 to A0 each held at
Command interface
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