18
March 3, 2005
A d v a n c e I n f o r m a t i o n
Command Definitions
Table 5.
Am29SL400C Command Definitions
Legend:
X = Don’t care
RA = Address of the memory location to be read.
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.
PD = Data to be programmed at location PA. Data latches on the rising edge of WE# or CE# pulse, whichever happens first.
SA = Address of the sector to be verified (in autoselect mode) or erased. Address bits A17–A12 uniquely select any sector.
Notes:
1.
See Table 1 for description of bus operations.
2.
All values are in hexadecimal.
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.
5.
Address bits A17–A11 are don’t cares for unlock and
command cycles, unless SA or PA required.
6.
No unlock or command cycles required when reading
array data, unless SA or PA required.
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).
8.
The fourth cycle of the autoselect command sequence is
a read cycle.
9.
The data is 00h for an unprotected sector and 01h for a
protected sector.
See “Autoselect Command
Sequence”
for more information.
10. The Unlock Bypass command is required prior to the
Unlock Bypass Program command.
11. The Unlock Bypass Reset command is required to return
to reading array data when the device is in the unlock
bypass mode.
12. 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.
13. The Erase Resume command is valid only during the Erase
Suspend mode.
Write Operation Status
The device provides several bits to determine the sta-
tus of a write operation: DQ2, DQ3, DQ5, DQ6, DQ7,
and RY/BY#.
Table 6 on page 22
and the following
Command
Sequence
(Note 1)
C
Bus Cycles (Notes 2-5)
Third
Dat
a
First
Second
Fourth
Fifth
Sixth
Addr
RA
XXX
555
AAA
555
AAA
555
AAA
Dat
a
RD
F0
Addr
Dat
a
Addr
Addr
Data
Addr
Dat
a
Addr
Dat
a
Read (Note 6)
Reset (Note 7)
1
1
A
Manufacturer ID
Word
Byte
Word
Byte
Word
Byte
4
AA
2AA
555
2AA
555
2AA
555
55
555
AAA
555
AAA
555
AAA
90
X00
01
Device ID,
Top Boot Block
4
AA
55
90
X01
X02
X01
X02
70h
70h
FIh
FIh
XX00
XX01
00
01
Device ID,
Bottom Boot Block
4
AA
55
90
Sector Protect Verify
(Note 9)
Word
4
555
AA
2AA
55
555
90
(SA)
X02
Byte
AAA
555
AAA
(SA)
X04
Program
Word
Byte
Word
Byte
4
555
AAA
555
AAA
XXX
XXX
555
AAA
555
AAA
XXX
XXX
AA
2AA
555
2AA
555
PA
XXX
2AA
555
2AA
555
55
555
AAA
555
AAA
A0
PA
PD
Unlock Bypass
3
AA
55
20
Unlock Bypass Program (Note 10)
Unlock Bypass Reset (Note 11)
2
2
A0
90
PD
00
Chip Erase
Word
Byte
Word
Byte
6
AA
55
555
AAA
555
AAA
80
555
AAA
555
AAA
AA
2AA
555
2AA
555
55
555
AAA
10
Sector Erase
6
AA
55
80
AA
55
SA
30
Erase Suspend (Note 12)
Erase Resume (Note 13)
1
1
B0
30