am49bds640ah Meet Spansion Inc., am49bds640ah Datasheet - Page 17

• Manufacturer Part Number: am49bds640ah
• Description: Stacked Multichip Package Mcp , Flash Memory And Psram Cmos 1.8 Volt-only Simultaneous Read/write, Burst Mode 64 Megabit 4m ? 16-bit Flash Memory, And 16 Mbit 1m ? 16-bit Psram
• Manufacturer: Meet Spansion Inc.

“bank address” is the address bits required to uniquely
select a bank. Similarly, a “sector address” is the
address bits required to uniquely select a sector.
I
represents the active current specification for the write
mode. The AC Characteristics section contains timing
specification tables and timing diagrams for write oper-
ations.
Accelerated Program Operation
The device offers accelerated program operations
through the ACC function. ACC is primarily intended to
allow faster manufacturing throughput at the factory.
If the system asserts V
matically enters the aforementioned Unlock Bypass
mode and uses the higher voltage on the input to
reduce the time required for program operations. The
system would use a two-cycle program command
sequence as required by the Unlock Bypass mode.
Removing V
to normal operation. Note that sectors must be
unlocked prior to raising ACC to V
ACC pin must not be at V
accelerated programming, or device damage may
result. In addition, the ACC pin must not be left floating
or unconnected; inconsistent behavior of the device
may result .
When at V
V
Autoselect Mode
The autoselect mode provides manufacturer and de-
vice identification, and sector protection verification,
through identifier codes output from the internal regis-
ter (which is separate from the memory array) on
DQ15–DQ0. This mode is primarily intended for pro-
gramming equipment to automatically match a device
to be programmed with its corresponding program-
ming algorithm. However, the autoselect codes can
also be accessed in-system through the command
register.
When using programming equipment, the autoselect
mode requires V
must be as shown in
Sector/Sector Block Addresses for Protection/Unpro-
tection,” on page
protection, the sector address must appear on the ap-
propriate highest order address bits (see
“Am49BDS640AH Boot Sector/Sector Block Ad-
December 5, 2003
CC2
IH
for all other conditions.
in the
IL
“DC Characteristics” section on page 45
, ACC locks all sectors. ACC should be at
HH
from the ACC input returns the device
ID
16. In addition, when verifying sector
on address pin A9. Address pins
Table 3, “Am49BDS640AH Boot
HH
on this input, the device auto-
HH
for operations other than
A D V A N C E
HH
. Note that the
Table 3,
Am49BDS640AH
I N F O R M A T I O N
dresses for Protection/Unprotection,” on page
Table 3
don’t care. When all necessary bits have been set as
required, the programming equipment may then read
the corresponding identifier code on DQ15–DQ0.
However, the autoselect codes can also be accessed
in-system through the command register, for instances
when the device is erased or programmed in a system
without access to high voltage on the A9 pin. The com-
mand sequence is illustrated in
Definitions,” on page
(BA) on address bits A22, A21, and A20 is asserted
during the third write cycle of the autoselect command,
the host system can read autoselect data that bank
and then immediately read array data from the other
bank, without exiting the autoselect mode.
To access the autoselect codes in-system, the host
system can issue the autoselect command via the
command register, as shown in
Definitions,” on page
V
when in the asynchronous read mode. Refer to the
“Autoselect Command Sequence” section on page 29
for more information.
ID
. Autoselect mode may only be entered and used
shows the remaining address bits that are
36. This method does not require
36. Note that if a Bank Address
Table 15, “Command
Table 15, “Command
16).
15