M29DW128F
Dual Operations and Multiple Bank architecture
8
Dual Operations and Multiple Bank architecture
The Multiple Bank Architecture of the M29DW128F gives greater flexibility for software developers to split
the code and data spaces within the memory array. The Dual Operations feature simplifies the software
management of the device by allowing code to be executed from one bank while another bank is being
programmed or erased.
The Dual Operations feature means that while programming or erasing in one bank, read operations are
possible in another bank with zero latency.
Only one bank at a time is allowed to be in program or erase mode. However, certain commands can
cross bank boundaries, which means that during an operation only the banks that are not concerned with
the cross bank operation are available for dual operations. For example, if a Block Erase command is
issued to erase blocks in both Bank A and Bank B, then only Banks C or D are available for read
operations while the erase is being executed.
If a read operation is required in a bank, which is programming or erasing, the program or erase
operation can be suspended.
Also if the suspended operation was erase then a program command can be issued to another block, so
the device can have one block in Erase Suspend mode, one programming and other banks in read mode.
By using a combination of these features, read operations are possible at any moment.
Table 20 and Table 21 show the dual operations possible in other banks and in the same bank. Note that
only the commonly used commands are represented in these tables.
Table 20. Dual Operations allowed in other Banks(1)
Commands allowed in another bank
Read
Status
Program/ Program/
Erase Erase
Suspend Resume
Status of Bank
Auto
Read/
Reset
ReadCFI
Query
Program Erase
Select
Register(2)
Idle
Yes
Yes
Yes
Yes
Yes
Yes(3)
No
Yes
No
Yes
No
Yes
–
Yes
–
Yes(3)
Yes(4)
No
Programming
No
No
-
Erasing
No
No
No
–
–
No
Program Suspended
Erase Suspended
No
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes(5)
Yes(6)
No
-
1. If several banks are involved in a program or erase operation, then only the banks that are not concerned with the
operation are available for dual operations.
2. Read Status Register is not a command. The Status Register can be read during a block program or erase operation.
3. Only after a program or erase operation in that bank.
4. Only after a Program or Erase Suspend command in that bank.
5. Only a Program Resume is allowed if the bank was previously in Program Suspend mode.
6. Only an Erase Resume is allowed if the bank was previously in Erase Suspend mode.
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NUMONYX [ NUMONYX B.V ]
