MBM29LV800TE/BE60/70/90
DQ2
Toggle Bit II
This toggle bit II, along with DQ6, can be used to determine whether the devices are in the Embedded Erase
Algorithm or in Erase Suspend.
Successive reads from the erasing sector will cause DQ2 to toggle during the Embedded Erase Algorithm. If the
devices are in the erase-suspended-read mode, successive reads from the erase-suspended sector will cause
DQ2 to toggle. When the devices are in the erase-suspended-program mode, successive reads from the byte
address of the non-erase suspended sector will indicate a logic “1” at the DQ2 bit.
DQ6 is different from DQ2 in that DQ6 toggles only when the standard program or Erase, or Erase Suspend
Program operation is in progress. The behavior of these two status bits, along with that of DQ7, is summarized
as follows :
For example, DQ2 and DQ6 can be used together to determine if the erase-suspend-read mode is in progress.
(DQ2 toggles while DQ6 does not.) See also “Hardware Sequence Flags” and “DQ2 vs. DQ6” in “■ TIMING
DIAGRAM”.
Furthermore, DQ2 can also be used to determine which sector is being erased. When device is in the erase
mode, DQ2 toggles if this bit is read from an erasing sector.
Toggle Bit Status
Mode
DQ7
DQ7
0
DQ6
DQ2
1
Program
Erase
Toggle
Toggle
Toggle
Erase-Suspend Read
1
1
Toggle
1 *2
(Erase-Suspended Sector) *1
Erase-Suspend Program
DQ7
Toggle *1
*1 : Performing successive read operations from any address will cause DQ6 to toggle.
*2 : Reading the byte address being programmed while in the erase-suspend program mode will indicate logic “1”
at the DQ2 bit. However, successive reads from the erase-suspended sector will cause DQ2 to toggle.
RY/BY
Ready/Busy
MBM29LV800TE/BE provide a RY/BY open-drain output pin as a way to indicate to the host system that Em-
bedded Algorithms are either in progress or has been completed. If output is low, devices are busy with either
a program or erase operation. If output is high, devices are ready to accept any read/write or erase operation.
If MBM29LV800TE/BE are placed in an Erase Suspend mode, RY/BY output will be high.
During programming, RY/BY pin is driven low after the rising edge of the fourth WE pulse. During an erase
operation, RY/BY pin is driven low after the rising edge of the sixth WE pulse. RY/BY pin will indicate a busy
condition during RESET pulse. Refer to “RY/BY Timing Diagram during Program/Erase Operation Timing
Diagram” and “RESET, RY/BY Timing Diagram” in “■ TIMING DIAGRAM” for a detailed timing diagram. RY/BY
pin is pulled high in standby mode.
Since this is an open-drain output, RY/BY pins can be tied together in parallel with a pull-up resistor to VCC.
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