EN29LV800 EON [Eon Silicon Solution Inc.], EN29LV800 Datasheet - Page 16

• Manufacturer Part Number: EN29LV800
• Description: 8 Megabit (1024K x 8-bit / 512K x 16-bit) Flash Memory Boot Sector Flash Memory, CMOS 3.0 Volt-only
• Manufacturer: EON [Eon Silicon Solution Inc.]

Reading Toggle Bits DQ6/DQ2
Refer to Flowchart 6 for the following discussion. Whenever the system initially begins reading toggle bit
status, it must read DQ7–DQ0 at least twice in a row to determine whether a toggle bit is toggling.
Typically, a system would note and store the value of the toggle bit after the first read. After the second
read, the system would compare the new value of the toggle bit with the first. If the toggle bit is not
toggling, the device has completed the program or erase operation. The system can read array data on
DQ7–DQ0 on the following read cycle.
However, if after the initial two read cycles, the system determines that the toggle bit is still toggling, the
system also should note whether the value of DQ5 is high (see the section on DQ5). If it is, the system
should then determine again whether the toggle bit is toggling, since the toggle bit may have stopped
toggling just as DQ5 went high. If the toggle bit is no longer toggling, the device has successfully
completed the program or erase operation. If it is still toggling, the device did not complete the operation
successfully, and the system must write the reset command to return to reading array data.
The remaining scenario is that the system initially determines that the toggle bit is toggling and DQ5 has
not gone high. The system may continue to monitor the toggle bit and DQ5 through successive read
cycles, determining the status as described in the previous paragraph. Alternatively, it may choose to
perform other system tasks. In this case, the system must start at the beginning of the algorithm when it
returns to determine the status of the operation (top of Flowchart 6).
Write Operation Status
Standard
4800 Great America Parkway, Suite 202
Santa Clara, CA 95054
Suspend
Erase
Mode
Mode
Embedded Erase Algorithm
Reading within Non-Erase
Erase-Suspend Program
Operation
Reading within Erase
Embedded Program
Suspended Sector
Suspended Sector
Algorithm
Rev 0.4 Release Date: 2002/01/29
DQ7#
DQ7#
Data
DQ7
0
1
16
Toggle
Toggle
Toggle
Toggle
DQ6
Data
No
Data
DQ5
0
0
0
0
DQ3
Data
N/A
N/A
N/A
1
EN29LV800
Tel: [phone]
Fax: [phone]
Toggle
Toggle
toggle
Data
DQ2
N/A
No
RY/BY
0
#
0
0
1
1