LON EN29F040A, Manual

Page: 8 / 35

This Data Sheet may be revised by subsequent versions ©2003 Eon Silicon Solution, Inc., www.essi.com.tw
or modifications due to changes in technical specifications.
8
EN29F040A
Rev. B, Issue Date: 2004/04/01
Table 5. EN29F040A Command Definitions
1
st
Write Cycle
2
nd
Write Cycle
3
rd
Write Cycle
4
th
Write Cycle
5
th
Write Cycle
6
th
Write Cycle
Command
Sequence
Read/Reset
Write
Cycles
Req’d
Addr Data Addr Data Addr Data Addr Data Addr Data Addr Data
Read
1 RA RD
Reset
1 XXXh F0h
Read/Reset
4 555h AAh 2AAh 55h 555h F0h RA RD
AutoSelect
Manufacturer ID
4 555h AAh 2AAh 55h 555h 90h
000h/
100h
7Fh/
1Ch
AutoSelect Device ID
4 555h AAh 2AAh 55h 555h 90h
001h/
101h
7Fh/
04h
AutoSelect Sector
Protect Verify
4 555h AAh 2AAh 55h 555h 90h
BA &
02h
00h/
01h
Byte Program
4 555h AAh 2AAh 55h 555h A0h PA PD
Chip Erase
6 555h AAh 2AAh 55h 555h 80h 555h AAh 2AAh 55h 555h 10h
Sector Erase
6 555h AAh 2AAh 55h 555h 80h 555h AAh 2AAh 55h SA 30h
Sector Erase Suspend
1 xxxh B0h
Sector Erase Resume
1 xxxh 30h
Notes:
RA = Read Address: address of the memory location to be read.
This one is a read cycle.
RD = Read Data: data read from location RA during Read operation.
This one is a read cycle.
PA = Program Address: address of the memory location to be programmed
PD = Program Data: data to be programmed at location PA
SA = Sector Address: address of the Sector to be erased. Address bits A18-A16 uniquely select any Sector.
The data is 00h for an unprotected sector and 01h for a protected sector.
Byte Programming Command
Programming the EN29F040A is performed on a byte-by-byte basis using a four bus-cycle operation
(two unlock write cycles followed by the Program Setup command and Program Data Write cycle).
When the program command is executed, no additional CPU controls or timings are necessary. An
internal timer terminates the program operation automatically. Address is latched on the falling edge
of CE or
W E
, whichever is last; data is latched on the rising edge of CE or
W E
, whichever is first.
The program operation is completed when EN29F040A returns the equivalent data to the
programmed location.
Programming status may be checked by sampling data on DQ7 ( DATA polling) or on DQ6 (toggle
bit). Changing data from 0 to 1 requires an erase operation. When programming time limit is
exceeded, DQ5 will produce a logical “1” and a Reset command can return the device to Read
mode.
Chip Erase Command
Chip erase is a six-bus-cycle operation. The chip erase command sequence is initiated by writing two
unlock cycles, followed by a set-up command. Two additional unlock write cycles are then followed by the
chip erase command, which in turn invokes the Embedded Erase algorithm. The device does
not require
the system to preprogram prior to erase. The Embedded Erase algorithm automatically preprograms and
verifies the entire memory for an all zero data pattern prior to electrical erase. The system is not required
to provide any controls or timings during these operations. The Command Definitions table shows the
address and data requirements for the chip erase command sequence.