EN29F080 Datasheet, PDF (7/37 Pages) List of Unclassifed Manufacturers – 8 Megabit (1024K x 8-bit) Flash Memory

EN29F080
Write Mode
Programming is a four-bus-cycle operation. The program command sequence is initiated by writing two
unlock write cycles, followed by the program set-up command. The program address and data are written
next, which in turn initiate the Embedded Program algorithm. The system is not required to provide further
controls or timings. The device automatically provides internally generated program pulses and verifies
the programmed cell margin. The Command Definitions in Table 5 show the address and data
requirements for the byte program command sequence.
When the Embedded Program algorithm is complete, the device then returns to reading array data and
addresses are no longer latched. The system can determine the status of the program operation by using
DQ7 or DQ6. See “Write Operation Status” for information on these status bits.
Any commands written to the device during the Embedded Program Algorithm are ignored.
Programming is allowed in any sequence and across sector boundaries. A bit cannot be programmed
from a “0” back to a “1”. Attempting to do so may halt the operation and set DQ5 to “1”, or cause the
Data# Polling algorithm to indicate the operation was successful. However, a succeeding read will show
that the data is still “0”. Only erase operations can convert a “0” to a “1”.
Sector Group Protection/Unprotection
The hardware sector protection feature disables
both program and erase operations in any sector.
Each group consists of two adjacent sectors. The
Sector Group Addresses table shows how the
sectors are grouped, and the address range that
each sector group contains. The hardware sector
group unprotection feature re-enables both program
and erase operations in previously protected sector
groups.
Sector
Group
SGA0
SGA1
SGA2
SGA3
SGA4
SGA5
SGA6
SGA7
Sector Group Addresses
A19
A18 A17 Sectors
0
0
0
SA0-SA1
0
0
1
SA2-SA3
0
1
0
SA4-SA5
0
1
1
SA6-SA7
1
0
0
SA8-SA9
1
0
1
SA10-SA11
1
1
0
SA12-SA13
1
1
1
SA14-SA15
Sector protection/unprotection must be implemented using programming equipment. The procedure re-
quires a high voltage (VID) on address pin A9 and the control pins. Details on this method are provided in
a supplement, which can be obtained by contacting a representative of Eon Silicon Devices, Inc.
Temporary Sector Group Unprotect
This feature allows temporary unprotection of previously protected
sector groups to change data while in-system. The Sector Group
Unprotect mode is activated by setting the RESET# pin to V_ID (10.5 V
to 11.5 V). During this mode, formerly protected sector groups can be
programmed or erased by simply selecting the sector group
addresses. Once V_ID is removed from the RESET# pin, all the
previously protected sector groups are protected again. See
accompanying figure and timing diagrams for more details.
Notes:
1. All protected sector groups unprotected.
2. Previously protected sector groups
protected again.
3. VIH = Logic High
Start
Reset#=VID (note 1)
Perform Erase or Program
Operations
Reset#=VIH
Temporary Sector Group
Unprotect Completed (note 2)
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Santa Clara, CA 95054
Rev. C, Issue Date: 2001/07/05
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