am49pdl127ah Meet Spansion Inc., am49pdl127ah Datasheet - Page 47

• Manufacturer Part Number: am49pdl127ah
• Description: Stacked Multi-chip Package Mcp Flash Memory And Psram, 128 Megabit 8m ? 16-bit Cmos 3.0 Volt-only, Simultaneous Operation Flash Memory And 16 Mbit 1m ? 16-bit Cmos Pseudo Static Ram
• Manufacturer: Meet Spansion Inc.

Enter SecSi™ Sector/Exit SecSi Sector
Command Sequence
The SecSi Sector region provides a secured data area
containing a random, eight word electronic serial num-
ber (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 Sector command sequence. The
Exit SecSi Sector command sequence returns the de-
vice to normal operation. The SecSi Sector is not ac-
cessible when the device is executing an Embedded
Program or embedded Erase algorithm. Table 16
shows the address and data requirements for both
command sequences. See also “SecSi™ (Secured Sili-
con) Sector Flash Memory Region” for further informa-
tion. Note that the ACC function and unlock bypass
modes are not available when the SecSi Sector is en-
abled.
Word Program Command Sequence
Programming is a four-bus-cycle operation. The pro-
gram 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 al-
gorithm. The system is not required to provide further
controls or timings. The device automatically provides
internally generated program pulses and verifies the
programmed cell margin. Table 16 shows the address
and data requirements for the program command se-
quence.
When the Embedded Program algorithm is complete,
that bank then returns to the read mode and ad-
dresses are no longer latched. The system can deter-
mine the status of the program operation by using
DQ7, DQ6, or RY/BY#. Refer to the Write Operation
Status section for information on these status bits.
Any commands written to the device during the Em-
bedded Program Algorithm are ignored. Note that a
hardware reset immediately terminates the program
operation. Note that the SecSi sector, autoselect, and
CFI functions are unavailable when the SecSi Sector
is enabled. The program command sequence should
be reinitiated once that bank has returned to the read
mode, to ensure data integrity.
December 18, 2003
A D V A N C E
Am49PDL127AH/Am49PDL129AH
I N F O R M A T I O N
Programming is allowed in any sequence and across
sector boundaries. A bit cannot be programmed
from “0” back to a “1.” Attempting to do so may
cause that bank to set DQ5 = 1, or cause the DQ7 and
DQ6 status bits to indicate the operation was success-
ful. However, a succeeding read will show 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 pro-
gram data to a bank faster than using the standard
program command sequence. The unlock bypass
command sequence is initiated by first writing two un-
lock cycles. This is followed by a third write cycle con-
taining the unlock bypass command, 20h. That bank
then enters the unlock bypass mode. A two-cycle un-
lock 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 com-
mand, 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-
ming time. Table 16 shows the requirements for the
command sequence.
During the unlock bypass mode, only the Unlock By-
pass Program and Unlock Bypass Reset commands
are valid. To exit the unlock bypass mode, the system
must issue the two-cycle unlock bypass reset com-
mand sequence.
The device offers accelerated program operations
through the WP#/ACC pin. When the system asserts
V
enters the Unlock Bypass mode. The system may then
write the two-cycle Unlock Bypass program command
sequence. The device uses the higher voltage on the
WP#/ACC pin to accelerate the operation. Note that
the WP#/ACC pin must not be at V
other than accelerated programming, or device dam-
age may result. In addition, the WP#/ACC pin must not
be left floating or unconnected; inconsistent behavior
of the device may result.
Figure 4 illustrates the algorithm for the program oper-
ation. Refer to the
table in the AC Characteristics section for parameters,
and Figures
HH
on the WP#/ACC pin, the device automatically
16
and
17
Erase and Program Operations
for timing diagrams.
HH
any operation
45