D A T A S H E E T
Table 5. Am29F400B Command Definitions
Bus Cycles (Notes 2–5)
Command
Sequence
(Note 1)
First
Second
Third
Addr
Fourth
Fifth
Sixth
Addr Data Addr Data
Data Addr Data Addr Data Addr Data
Read (Note 6)
Reset (Note 7)
1
1
RA
XXX
555
RD
F0
Word
Byte
Word
Byte
Word
Byte
2AA
555
2AA
555
2AA
555
555
AAA
555
Manufacturer ID
4
4
4
AA
AA
AA
55
55
55
90
90
90
X00
01
AAA
555
X01
X02
2223
23
Device ID,
Top Boot Block
AAA
555
AAA
555
X01 22AB
Device ID,
Bottom Boot Block
AAA
AAA
X02
AB
XX00
XX01
00
(SA)
X02
Word
Byte
555
2AA
555
555
Sector Protect Verify
(Note 9)
4
AA
55
90
(SA)
X04
AAA
AAA
01
Word
Byte
Word
Byte
Word
Byte
555
AAA
555
2AA
555
2AA
555
2AA
555
555
AAA
555
Program
4
6
6
AA
AA
AA
55
55
55
A0
80
80
PA
PD
AA
AA
555
AAA
555
2AA
555
2AA
555
555
Chip Erase
55
55
10
30
AAA
555
AAA
555
AAA
Sector Erase
SA
AAA
XXX
XXX
AAA
AAA
Erase Suspend (Note 10)
Erase Resume (Note 11)
1
1
B0
30
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 A17–A12 uniquely select any 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.
8. The fourth cycle of the autoselect command sequence is a
read cycle.
2. All values are in hexadecimal.
9. 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. Data bits DQ15–DQ8 are don’t cares for unlock and
command cycles.
10. 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. Address bits A17–A11 are don’t cares for unlock and
command cycles, unless PA or SA required.
6. No unlock or command cycles required when reading array
data.
11. The Erase Resume command is valid only during the Erase
Suspend mode.
7. 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).
November 11, 2009 21505E8
Am29F400B
17
CYPRESS [ CYPRESS ]
