Harman Kardon AVR145/230, Service Manual

Page: 96 / 135

M29W800DT, M29W800DB
Erase Suspend Command. The Erase Suspend
Command may be used to temporarily suspend a
Block Erase operation and return the memory to
Read mode. The command requires one Bus
Write operation.
The Program/Erase Controller will suspend within
the Erase Suspend Latency Time (refer to
Table 6.
for value) of the Erase Suspend Command being
issued. Once the Program/Erase Controller has
stopped the memory will be set to Read mode and
the Erase will be suspended. If the Erase Suspend
command is issued during the period when the
memory is waiting for an additional block (before
the Program/Erase Controller starts) then the
Erase is suspended immediately and will start im-
mediately when the Erase Resume Command is
issued. It is not possible to select any further
blocks to erase after the Erase Resume.
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. Read-
ing from blocks that are being erased will output
the Status Register.
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 ac-
cepted.
Erase Resume Command. The Erase Resume
command must be used to restart the Program/
Erase Controller from Erase Suspend. An erase
can be suspended and resumed more than once.
Read CFI Query Command. The Read CFI
Query Command is used to read data from the
Common Flash Interface (CFI) Memory Area. This
command is valid when the device is in the Read
Array mode, or when the device is in Auto Select
mode.
One Bus Write cycle is required to issue the Read
CFI Query Command. Once the command is is-
sued subsequent Bus Read operations read from
the Common Flash Interface Memory Area.
The Read/Reset command must be issued to re-
turn the device to the previous mode (the Read Ar-
ray mode or Auto Select mode). A second Read/
Reset command would be needed if the device is
to be put in the Read Array mode from Auto Select
mode.
See
APPENDIX B. , Tables 23 , 24 , 25 , 26 , 27 and
28 for details on the information contained in the
Common Flash Interface (CFI) memory area.
Block Protect and Chip Unprotect Commands.
Each block can be separately protected against
accidental Program or Erase. The whole chip can
be unprotected to allow the data inside the blocks
to be changed.
Block Protect and Chip Unprotect operations are
described in
APPENDIX C.
harman/kardon AVR 145/230 service manual
Page 96 of 135