During Erase Suspend it is possible to Read and Program cells in blocks that are not being
erased; both Read and Program operations behave as normal on these blocks. If any
attempt is made to program in a protected block or in the suspended block then the Program
command is ignored and the data remains unchanged. The Status register is not read and
no error condition is given. Reading from blocks that are being erased will output the Status
It is also possible to issue the Auto Select, Read CFI Query and Unlock Bypass commands
during an Erase Suspend. The Read/Reset command must be issued to return the device to
Read Array mode before the Resume command will be accepted.
During Erase Suspend a Bus Read operation to the Extended Block will output the
Extended Block data.
Erase Resume command
The Erase Resume command must be used to restart the Program/Erase Controller after an
Erase Suspend. The device must be in Read Array mode before the Resume command will
be accepted. An erase can be suspended and resumed more than once.
Enter Extended Block command
The M29W320E has an extra 64Kbyte block (Extended Block) that can only be accessed
using the Enter Extended Block command. Three Bus write cycles are required to issue the
Extended Block command. Once the command has been issued the device enters
Extended Block mode where all Bus Read or Program operations to the Boot Block
addresses access the Extended Block. The Extended Block (with the same address as the
boot block) cannot be erased, and can be treated as one-time programmable (OTP)
memory. In Extended Block mode the Boot Blocks are not accessible.
To exit from the Extended Block mode the Exit Extended Block command must be issued.
The Extended Block can be protected, however once protected the protection cannot be
Exit Extended Block command
The Exit Extended Block command is used to exit from the Extended Block mode and return
the device to Read mode. Four Bus Write operations are required to issue the command.
Block Protect and Chip Unprotect commands
Groups of blocks can be protected against accidental Program or Erase. The Protection
groups are shown in Appendix A: Block Addresses, Table 20 and Table 21, Block
Addresses. The whole chip can be unprotected to allow the data inside the blocks to be
Block Protect and Chip Unprotect operations are described in Appendix D: Block Protection.