Command Definitions
Table 4. Am29F040B Command Definitions
Bus Cycles (Notes 2–4)
Command
Sequence
(Note 1)
First
Second
Third
Addr
Fourth
Fifth
Sixth
Addr Data Addr Data
Data Addr Data Addr Data Addr Data
Read (Note 5)
Reset (Note 6)
Manufacturer ID
1
1
4
4
RA
XXX
555
555
RD
F0
AA
AA
2AA
2AA
55
55
555
555
90
90
X00
X01
01
A4
00
Autoselect
Device ID
(Note 7)
Sector Protect Verify
(Note 8)
SA
X02
4
555
AA
2AA
55
555
90
01
Program
4
6
6
1
1
555
555
AA
AA
AA
B0
30
2AA
2AA
2AA
55
55
55
555
555
555
A0
80
80
PA
555
555
PD
AA
AA
Chip Erase
2AA
2AA
55
55
555
SA
10
30
Sector Erase
555
Erase Suspend (Note 9)
Erase Resume (Note 10)
XXX
XXX
Legend:
X = Don’t care
PD = Data to be programmed at location PA. Data latches on the
rising edge of WE# or CE# pulse, whichever happens first.
RA = Address of the memory location to be read.
SA = Address of the sector to be verified (in autoselect mode) or
erased. Address bits A18–A16 select a unique sector.
RD = Data read from location RA during read operation.
PA = Address of the memory location to be programmed.
Addresses latch on the falling edge of the WE# or CE# pulse,
whichever happens later.
Notes:
1. See Table 1 for description of bus operations.
7. The fourth cycle of the autoselect command sequence is a
read cycle.
2. All values are in hexadecimal.
8. The data is 00h for an unprotected sector and 01h for a
protected sector.See “Autoselect Command Sequence” for
more information.
3. Except when reading array or autoselect data, all bus cycles
are write operations.
4. Address bits A18–A11 are don’t cares for unlock and
command cycles, unless SA or PA required.
9. The system may read and program in non-erasing sectors, or
enter the autoselect mode, when in the Erase Suspend
mode. The Erase Suspend command is valid only during a
sector erase operation.
5. No unlock or command cycles required when reading array data.
6. The Reset command is required to return to reading array
data when device is in the autoselect mode, or if DQ5 goes
high (while the device is providing status data).
10. The Erase Resume command is valid only during the Erase
Suspend mode.
14
Am29F040B
AMD [ AMD ]
