at52bc3221a ATMEL Corporation, at52bc3221a Datasheet - Page 6

• Manufacturer Part Number: at52bc3221a
• Description: 32-mbit Flash 8-mbit Psram Stack Memory
• Manufacturer: ATMEL Corporation

6
AT52BC3221A(T)
VPP PIN: The circuitry of the 32-Mbit Flash is designed so that the device cannot be pro-
grammed or erased if the V
program and erase operations can be performed. The VPP pin cannot be left floating.
PROGRAM/ERASE STATUS: The device provides several bits to determine the status of a
program or erase operation: I/O2, I/O3, I/O5, I/O6 and I/O7. The “Status Bit Table” on page 11
and the following four sections describe the function of these bits. To provide greater flexibility
for system designers, the device contains a programmable configuration register. The configu-
ration register allows the user to specify the status bit operation. The configuration register can
be set to one of two different values, “00” or “01”. If the configuration register is set to “00”, the
part will automatically return to the read mode after a successful program or erase operation. If
the configuration register is set to a “01”, a Product ID Exit command must be given after a
successful program or erase operation before the part will return to the read mode. It is impor-
tant to note that whether the configuration register is set to a “00” or to a “01”, any
unsuccessful program or erase operation requires using the Product ID Exit command to
return the device to read mode. The default value (after power-up) for the configuration regis-
ter is “00”. Using the four-bus cycle Set Configuration Register command as shown in the
“Command Definition in Hex” table on page 12, the value of the configuration register can be
changed. Voltages applied to the RESET pin will not alter the value of the configuration regis-
ter. The value of the configuration register will affect the operation of the I/O7 status bit as
described below.
DATA POLLING: The device features Data Polling to indicate the end of a program cycle. If
the status configuration register is set to a “00”, during a program cycle an attempted read of
the last word loaded will result in the complement of the loaded data on I/O7. Once the pro-
gram cycle has been completed, true data is valid on all outputs and the next cycle may begin.
During a chip or sector erase operation, an attempt to read the device will give a “0” on I/O7.
Once the program or erase cycle has completed, true data will be read from the device. Data
Polling may begin at any time during the program cycle. Please see “Status Bit Table” on page
11 for more details.
If the status bit configuration register is set to a “01”, the I/O7 status bit will be low while the
device is actively programming or erasing data. I/O7 will go high when the device has com-
pleted a program or erase operation. Once I/O7 has gone high, status information on the other
pins can be checked.
The Data Polling status bit must be used in conjunction with the erase/program and V
bit as shown in the algorithm in Figures 1 and 2 on page 9.
TOGGLE BIT: In addition to Data Polling the device provides another method for determining
the end of a program or erase cycle. During a program or erase operation, successive
attempts to read data from the memory will result in I/O6 toggling between one and zero. Once
the program cycle has completed, I/O6 will stop toggling and valid data will be read. Examin-
ing the toggle bit may begin at any time during a program cycle. Please see “Status Bit Table”
on page 11 for more details.
The toggle bit status bit should be used in conjunction with the erase/program and V
bit as shown in the algorithm in Figures 3 and 4 on page 10.
ERASE/PROGRAM STATUS BIT: The device offers a status bit on I/O5, which indicates
whether the program or erase operation has exceeded a specified internal pulse count limit. If
the status bit is a “1”, the device is unable to verify that an erase or a word program operation
has been successfully performed. If a program (Sector Erase) command is issued to a pro-
tected sector, the protected sector will not be programmed (erased). The device will go to a
status read mode and the I/O5 status bit will be set high, indicating the program (erase) opera-
tion did not complete as requested. Once the erase/program status bit has been set to a “1”,
the system must write the Product ID Exit command to return to the read mode. The
PP
voltage is less that 0.4V. When V
PP
is at 0.9V or above, normal
3466A–STKD–11/04
PP
PP
status
status