AT49BV001A-55TI Atmel, AT49BV001A-55TI Datasheet - Page 5

• Manufacturer Part Number: AT49BV001A-55TI
• Description: IC FLASH 1MBIT 55NS 32TSOP
• Manufacturer: Atmel

Specifications of AT49BV001A-55TI

• Format - Memory: FLASH
• Memory Type: FLASH
• Memory Size: 1M (128K x 8)
• Speed: 55ns
• Interface: Parallel
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.6.1
4.6.2
4.7
4.8
4.9
4.10
3364D–FLASH–3/05
Product Identification
DATA Polling
Toggle Bit
Hardware Data Protection
Boot Block Lockout Detection
Boot Block Programming Lockout Override
Once the feature is enabled, the data in the boot block can no longer be erased or programmed
with input voltage of 5.5V or less. Data in the main memory block can still be changed through
the regular programming method. To activate the lockout feature, a series of six program com-
mands to specific addresses with specific data must be performed. Please refer to the
“Command Definition Table” on page
A software method is available to determine if programming of the boot block section is locked
out. When the device is in the software product identification mode (see Software Product Iden-
tification Entry and Exit sections) a read from address location 00002H will show if programming
the boot block is locked out for the AT49BV001A(N), and a read from address location 1C002H
will show if programming the boot block is locked out for the AT49BV001A(N)T. If the data on
I/O0 is low, the boot block can be programmed; if the data on I/O0 is high, the program lockout
feature has been activated and the block cannot be programmed. The software product identifi-
cation code should be used to return to standard operation.
The user can override the boot block programming lockout by taking the RESET pin to 12 volts
during the entire chip erase, sector erase or byte programming operation. When the RESET pin
is brought back to TTL levels the boot block programming lockout feature is again active. This
feature is not available on the AT49BV001AN(T).
The product identification mode identifies the device and manufacturer as Atmel. It may be
accessed by hardware or software operation. The hardware operation mode can be used by an
external programmer to identify the correct programming algorithm for the Atmel product.
For details, see
Identification. The manufacturer and device code is the same for both modes.
The AT49BV001A(N)(T) features DATA polling to indicate the end of a program cycle. During a
program cycle an attempted read of the last byte loaded will result in the complement of the
loaded data on I/O7. Once the program cycle has been completed, true data is valid on all out-
puts and the next cycle may begin. DATA polling may begin at any time during the program
cycle.
In addition to DATA polling the AT49BV001A(N)(T) 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 device 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. Examining the toggle bit
may begin at any time during a program cycle.
Hardware features protect against inadvertent programs to the AT49BV001A(N)(T) in the follow-
ing ways: (a) V
Program inhibit: holding any one of OE low, CE high or WE high inhibits program cycles. (c)
Noise filter: pulses of less than 15 ns (typical) on the WE or CE inputs will not initiate a program
cycle.
CC
“Operating Modes” on page 7
sense: if V
CC
is below 1.8V (typical), the program function is inhibited. (b)
6.
(for hardware operation) or Software Product
AT49BV001A(N)(T)
5