nection allows for OR-tying of several devices to the same RDY/BUSY line. Please see
CFI:
Common Flash Interface (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 deter-
mine 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 Table 1
on page 24. To exit the CFI Query mode, the product ID exit command must be given.
HARDWARE DATA PROTECTION:
The Hardware Data Protection feature protects against
inadvertent programs to the AT49BV162A(T)/163A(T) in the following ways: (a) V
CC
sense: if
V
CC
is below 1.8V (typical), the program function is inhibited. (b) V
CC
power-on delay: once
V
CC
has reached the V
CC
sense level, the device will automatically time out 10 ms (typical)
before programming. (c) Program inhibit: holding any one of OE low, CE high or WE high
inhibits program cycles. (d) Program inhibit: V
PP
is less than V
ILPP
. (e) V
PP
power-on delay:
once V
PP
has reached 1.65V, program and erase operations are inhibited for 100 ns.
INPUT LEVELS:
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
CC
+ 0.6V.
8
AT49BV162/163A(T)
3349G–FLASH–7/04
ATMEL [ ATMEL CORPORATION ]
