M50FW016N1TG View Datasheet(PDF) - STMicroelectronics
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M50FW016N1TG Datasheet PDF : 45 Pages
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M50FW016
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.
After power-up or a Reset operation the memory
enters Read mode.
The commands are summarized in Table
10., Commands. Refer to Table 10. in conjunction
with the text descriptions below.
Read Memory Array Command. The Read Mem-
ory Array command returns the memory to its
Read mode where it behaves like a ROM or
EPROM. One Bus Write cycle is required to issue
the Read Memory Array command and return the
memory to Read mode. Once the command is is-
sued the memory remains in Read mode until an-
other command is issued. From Read mode Bus
Read operations will access the memory array.
While the Program/Erase Controller is executing a
Program or Erase operation the memory will not
accept the Read Memory Array command until the
operation completes.
Read Status Register Command. The Read Sta-
tus Register command is used to read the Status
Register. One Bus Write cycle is required to issue
the Read Status Register command. Once the
command is issued subsequent Bus Read opera-
tions read the Status Register until another com-
mand is issued. See the section on the STATUS
REGISTER for details on the definitions of the Sta-
tus Register bits.
Read Electronic Signature Command. The Read
Electronic Signature command is used to read the
Manufacturer Code and the Device Code. One
Bus Write cycle is required to issue the Read
Electronic Signature command. Once the
command is issued subsequent Bus Read
operations read the Manufacturer Code or the
Device Code until another command is issued.
After the Read Electronic Signature Command is
issued the Manufacturer Code and Device Code
can be read using Bus Read operations using the
addresses in Table 9.
Program Command. The Program command
can be used to program a value to one address in
the memory array at a time. Two Bus Write
operations are required to issue the command; the
second Bus Write cycle latches the address and
data in the internal state machine and starts the
Program/Erase Controller. Once the command is
issued subsequent Bus Read operations read the
Status Register. See the section on the STATUS
REGISTER for details on the definitions of the
Status Register bits.
If the address falls in a protected block then the
Program operation will abort, the data in the
memory array will not be changed and the Status
Register will output the error.
During the Program operation the memory will
only accept the Read Status Register command
and the Program/Erase Suspend command. All
other commands will be ignored. Typical Program
times are given in Table 15.
Note that the Program command cannot change a
bit set at ‘0’ back to ‘1’ and attempting to do so will
not cause any modification on its value. One of the
Erase commands must be used to set all of the
bits in the block to ‘1’.
See Figure 16., Program Flowchart and Pseudo
Code, for a suggested flowchart on using the
Program command.
Quadruple Byte Program Command (A/A Mux
Mode). The Quadruple Byte Program Command
can be used to program four adjacent bytes in the
memory array at a time. The four bytes must differ
only for the addresses A0 and A1. Programming
should not be attempted when VPP is not at VPPH.
Five Bus Write operations are required to issue the
command. The second, the third and the fourth
Bus Write cycle latches respectively the address
and data of the first, the second and the third byte
in the internal state machine. The fifth Bus Write
cycle latches the address and data of the fourth
byte in the internal state machine and starts the
Program/Erase Controller. Once the command is
issued subsequent Bus Read operations read the
Status Register. See the section on the STATUS
REGISTER for details on the definitions of the
Status Register bits.
During the Quadruple Byte Program operation the
memory will only accept the Read Status register
command and the Program/Erase Suspend com-
mand. All other commands will be ignored. Typical
Quadruple Byte Program times are given in Table
15..
Note that the Quadruple Byte Program command
cannot change a bit set to ‘0’ back to ‘1’ and
attempting to do so will not cause any modification
on its value. One of the Erase commands must be
used to set all of the bits in the block to ‘1’.
See Figure 17., for a suggested flowchart on using
the Quadruple Byte Program command.
Quadruple Byte Program Command (FWH
Mode). The Quadruple Byte Program Command
can be used to program four adjacent bytes in the
memory array at a time. The four bytes must differ
only for the addresses A0 and A1. Programming
should not be attempted when VPP is not at VPPH.
Two Bus Write operations are required to issue the
command. The second Bus Write cycle latches the
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