M29F040B70N6 NUMONYX, M29F040B70N6 Datasheet - Page 6

• Manufacturer Part Number: M29F040B70N6
• Description: IC FLASH 4MBIT 70NS 32TSOP
• Manufacturer: NUMONYX

Specifications of M29F040B70N6

• Format - Memory: FLASH
• Memory Type: FLASH - Nor
• Memory Size: 4M (512K x 8)
• Speed: 70ns
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

M29F040B
COMMAND INTERFACE
All Bus Write operations to the memory are inter-
preted by the Command Interface. Commands
consist of one or more sequential Bus Write oper-
ations. Failure to observe a valid sequence of Bus
Write operations will result in the memory return-
ing to Read mode. The long command sequences
are imposed to maximize data security.
The commands are summarized in Table 5, Com-
mands. Refer to Table 5 in conjunction with the
text descriptions below.
Read/Reset Command. The Read/Reset com-
mand returns the memory to its Read mode where
it behaves like a ROM or EPROM. 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.
If the Read/Reset command is issued during a
Block Erase operation or following a Programming
or Erase error then the memory will take up to 10
to abort. During the abort period no valid data can
be read from the memory. Issuing a Read/Reset
command during a Block Erase operation will
leave invalid data in the memory.
Auto Select Command. The Auto Select com-
mand is used to read the Manufacturer Code, the
Device Code and the Block Protection Status.
Three consecutive Bus Write operations are re-
quired to issue the Auto Select command. Once
the Auto Select command is issued the memory
remains in Auto Select mode until another com-
mand is issued.
From the Auto Select mode the Manufacturer
Code can be read using a Bus Read operation
with A0 = V
may be set to either V
Code for STMicroelectronics is 20h.
The Device Code can be read using a Bus Read
operation with A0 = V
address bits may be set to either V
Device Code for the M29F040B is E2h.
The Block Protection Status of each block can be
read using a Bus Read operation with A0 = V
A1 = V
dress of the block. The other address bits may be
set to either V
protected then 01h is output on the Data Inputs/
Outputs, otherwise 00h is output.
Program Command. The Program command
can be used to program a value to one address in
the memory array at a time. The command re-
quires four Bus Write operations, the final write op-
eration latches the address and data in the internal
6/21
IH
, and A16, A17 and A18 specifying the ad-
IL
and A1 = V
IL
or V
IH
IL
IH
. If the addressed block is
or V
IL
and A1 = V
. The other address bits
IH
. The Manufacturer
IL
IL
or V
. The other
IH
. The
µs
IL
,
state machine and starts the Program/Erase Con-
troller.
If the address falls in a protected block then the
Program command is ignored, the data remains
unchanged. The Status Register is never read and
no error condition is given.
During the program operation the memory will ig-
nore all commands. It is not possible to issue any
command to abort or pause the operation. Typical
program times are given in Table 6. Bus Read op-
erations during the program operation will output
the Status Register on the Data Inputs/Outputs.
See the section on the Status Register for more
details.
After the program operation has completed the
memory will return to the Read mode, unless an
error has occurred. When an error occurs the
memory will continue to output the Status Regis-
ter. A Read/Reset command must be issued to re-
set the error condition and return to Read mode.
Note that the Program command cannot change a
bit set at ’0’ back to ’1’. One of the Erase Com-
mands must be used to set all the bits in a block or
in the whole memory from ’0’ to ’1’.
Unlock Bypass Command. The Unlock Bypass
command is used in conjunction with the Unlock
Bypass Program command to program the memo-
ry. When the access time to the device is long (as
with some EPROM programmers) considerable
time saving can be made by using these com-
mands. Three Bus Write operations are required
to issue the Unlock Bypass command.
Once the Unlock Bypass command has been is-
sued the memory will only accept the Unlock By-
pass Program command and the Unlock Bypass
Reset command. The memory can be read as if in
Read mode.
Unlock Bypass Program Command. The
lock Bypass Program command can be used to
program one address in memory at a time. The
command requires two Bus Write operations, the
final write operation latches the address and data
in the internal state machine and starts the Pro-
gram/Erase Controller.
The Program operation using the Unlock Bypass
Program command behaves identically to the Pro-
gram operation using the Program command. A
protected block cannot be programmed; the oper-
ation cannot be aborted and the Status Register is
read. Errors must be reset using the Read/Reset
command, which leaves the device in Unlock By-
pass Mode. See the Program command for details
on the behavior.
Un-