Classic EPLD Family Data Sheet
EP610, EP610I, EP910, and EP910I devices have a global feedback
configuration; either the macrocell output (Q) or the I/O pin input (I/O)
can feed back to the
AND
array so that it is accessible to all other
macrocells.
EP1810 macrocells can have either of two feedback configurations:
quadrant or dual. Most macrocells in EP1810 devices have a quadrant
feedback configuration; either the macrocell output or I/O pin input can
feed back to other macrocells in the same quadrant. Selected macrocells in
EP1810 devices have a dual feedback configuration: the output of the
macrocell feeds back to other macrocells in the same quadrant, and the
I/O pin input feeds back to all macrocells in the device. If the associated
I/O pin is not used, the macrocell output can optionally feed all
macrocells in the device. In this case, the output of the macrocell passes
through the tri-state buffer and uses the feedback path between the buffer
and the I/O pin.
Design Security
Classic devices contain a programmable security bit that controls access to
the data programmed into the device. When this bit is programmed, a
proprietary design implemented in the device cannot be copied or
retrieved. This feature provides a high level of design security because
data within configuration elements is invisible. The security bit that
controls this function and other program data is reset only when the
device is erased.
Device timing can be analyzed with the MAX+PLUS II software, with a
variety of popular industry-standard EDA simulators and timing
analyzers, or with the timing model shown in
Figure 4.
Devices have fixed
internal delays that allow the user to determine the worst-case timing for
any design. The MAX+PLUS II software provides timing simulation,
point-to-point delay prediction, and detailed timing analysis for system-
level performance evaluation.
Timing Model
Figure 4. Classic Timing Model
Global Clock
Delay
t
ICS
Input
Delay
t
IN
Array Clock
Delay
t
IC
Logic Array
Delay
t
LAD
t
CLR
I/O
Delay
t
IO
Feedback
Delay
t
FD
Register
t
SU
t
H
Output
Delay
t
OD
t
XZ
t
ZX
750
Altera Corporation
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