at49bv163d ATMEL Corporation, at49bv163d Datasheet - Page 7

• Manufacturer Part Number: at49bv163d
• Description: 16-megabit 1m X 16/2m X 8 3-volt Only Flash Memory
• Manufacturer: ATMEL Corporation

4.11
4.12
4.13
4.14
4.15
3590A–FLASH–12/05
128-bit Protection Register
RDY/BUSY
Common Flash Interface (CFI)
Hardware Data Protection
Input Levels
The AT49BV163D(T) contains a 128-bit register that can be used for security purposes in sys-
tem design. The protection register is divided into two 64-bit blocks. The two blocks are
designated as block A and block B. The data in block A is non-changeable and is programmed
at the factory with a unique number. The data in block B is programmed by the user and can be
locked out such that data in the block cannot be reprogrammed. To program block B in the pro-
tection register, the four-bus cycle Program Protection Register command must be used as
shown in the
Lock Protection Register command must be used as shown in the
Data bit D1 must be zero during the fourth bus cycle. All other data bits during the fourth bus
cycle are don’t cares. To determine whether block B is locked out, the Product ID Entry com-
mand is given followed by a read operation from address 80H. If data bit D1 is zero, block B is
locked. If data bit D1 is one, block B can be reprogrammed. Please see the
Addressing Table” on page 12
protection register, the Product ID Entry command is given followed by a normal read operation
from an address within the protection register. After determining whether block B is protected or
not, or reading the protection register, the Product ID Exit command must be given prior to per-
forming any other operation.
An open-drain READY/BUSY output pin provides another method of detecting the end of a pro-
gram or erase operation. RDY/BUSY is actively pulled low during the internal program and erase
cycles and is released at the completion of the cycle. The open-drain connection allows for OR-
tying of several devices to the same RDY/BUSY line. Please see
for more details.
CFI is a published, standardized data structure that may be read from a flash device. CFI allows
system software to query the installed device to determine the configurations, various electrical
and timing parameters, and functions supported by the device. CFI is used to allow the system
to learn how to interface to the flash device most optimally. The two primary benefits of using
CFI are ease of upgrading and second source availability. The command to enter the CFI Query
mode is a one-bus cycle command which requires writing data 98h to address 55h. The CFI
Query command can be written when the device is ready to read data or can also be written
when the part is in the product ID mode. Once in the CFI Query mode, the system can read CFI
data at the addresses given in
the CFI Query mode, the product ID exit command must be given.
The Hardware Data Protection feature protects against inadvertent programs to the
AT49BV163D(T) in the following ways: (a) V
function is inhibited. (b) Program inhibit: holding any one of OE low, CE high or WE high inhibits
program cycles.
While operating with a 2.65V to 3.6V power supply, the address inputs and control inputs (OE,
CE and WE) may be driven from 0 to 5.5V without adversely affecting the operation of the
device. The I/O lines can only be driven from 0 to V
“Command Definition Table” on page
for the address locations in the protection register. To read the
“Common Flash Interface Definition Table” on page
CC
sense: if V
CC
11. To lock out block B, the four-bus cycle
+ 0.6V.
CC
is below 1.8V (typical), the program
AT49BV163D(T)
“Status Bit Table” on page 10
“Command Definition Table”
“Protection Register
22. To exit
7
.