AM29SL160C AMD [Advanced Micro Devices], AM29SL160C Datasheet - Page 24

• Manufacturer Part Number: AM29SL160C
• Description: 16 Megabit CMOS 1.8 Volt-only Super Low Voltage Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

before programming begins. This resets the device to
reading array data (also applies to programming in
Erase Suspend mode). Once programming begins,
however, the device ignores reset commands until the
operation is complete.
The reset command may be written between the
sequence cycles in an autoselect command sequence.
Once in the autoselect mode, the reset command must
be written to return to reading array data (also applies
to autoselect during Erase Suspend).
If DQ5 goes high during a program or erase operation,
writing the reset command returns the device to
reading array data (also applies during Eras e
Suspend).
See
to
Autoselect Command Sequence
The autoselect command sequence allows the host
system to access the manufacturer and device codes,
and determine whether or not a sector is protected.
Table 12, on page 28
requirements. This method is an alternative to that
shown in
PROM programmers and requires V
A9.
The autoselect command sequence is initiated by
writing two unlock cycles, followed by the autoselect
command. The device then enters the autoselect
mode, and the system may read at any address any
number of times, without initiating another command
sequence. A read cycle at address XX00h retrieves the
manufacturer code. A read cycle at address 01h in
word mode (or 02h in byte mode) returns the device
code. A read cycle containing a sector address (SA)
and the address 02h in word mode (or 04h in byte
mode) returns 01h if that sector is protected, or 00h if it
is unprotected. Refer to
Table 3, on page 15
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Enter SecSi Sector/Exit SecSi Sector Com-
mand Sequence
The SecSi Sector region provides a secured data area
containing a random, sixteen-byte electronic serial
number (ESN). The system can access the SecSi
Sector region by issuing the three-cycle Enter SecSi
Sector command sequence. The device continues to
access the SecSi Sector region until the system issues
the four-cycle Exit SecSi command sequence. The Exit
SecSi command sequence returns the device to
normal operation.
address and data requirements for both command
sequences. See also
24
Figure 14, on page 38
“AC Characteristics” on page 37
Table 4, on page
Table 12, on page 28
for valid sector addresses.
“Secured Silicon (SecSi) Sector
shows the address and data
for the timing diagram.
Table 2, on page 14
16, which is intended for
for parameters, and
ID
on address bit
shows the
Am29SL160C
and
F lash Memory R egion” on page 20
information.
Word/Byte Program Command Sequence
The system may program the device by word or byte,
depending on the state of the BYTE# pin. Program-
ming 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 tim-
ings. The device automatically generates the program
pulses and verifies the programmed cell margin.
Table 12, on page 28
r e q ui r e m en ts f or th e by te pr o gr a m co m m a n d
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, DQ6, or RY/BY#. See
on page 29
Any commands written to the device during the
Embedded Program Algorithm are ignored. Note that a
hardware reset immediately terminates the program-
m i ng op er a tio n. T h e B y te P ro gr am co m ma n d
sequence should be reinitiated once the device resets
to reading array data, to ensure data integrity.
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 suc-
cessful. However, a succeeding read shows that the
data is still “0”. Only erase operations can convert a “0”
to a “1”.
Unlock Bypass Command Sequence
The unlock bypass feature allows the system to
program bytes or words to the device faster than using
the standard program command sequence. The unlock
bypass command sequence is initiated by first writing
two unlock cycles. This is followed by a third write cycle
containing the unlock bypass command, 20h. The
device then enters the unlock bypass mode. A two-
cycle unlock bypass program command sequence is all
that is required to program in this mode. The first cycle
in this sequence contains the unlock bypass program
command, A0h; the second cycle contains the program
address and data. Additional data is programmed in the
same manner. This mode dispenses with the initial two
unlock cycles required in the standard program
command sequence, resulting in faster total program-
m i n g t i m e .
requirements for the command sequence.
for information on these status bits.
Ta b l e 1 2 , o n p a g e 2 8
shows the address and data
“Write Operation Status”
November 1, 2004
s h o w s t h e
for further