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MOBILE PENTIUM PROCESSOR WITH MMX™ TECHNOLOGY
4.4.
I/O Buffer Models
This section describes the I/O buffer models of the
mobile Pentium processor with MMX technology on
0.25 Micron.
The first order I/O buffer model is a simplified
representation of the complex input and output
buffers used. Figure 10 shows the structure of the
input buffer model and Figure 11 shows the output
buffer model. Tables 17 and 18 show the
parameters used to specify these models.
Although simplified, these buffer models will
accurately model flight time and signal quality. For
these parameters, there is very little added
accuracy in a complete transistor model.
In addition to the input and output buffer
parameters, input protection diode models are
provided for added accuracy. These diodes have
been optimized to provide ESD protection and
provide some level of clamping. Although the
diodes are not required for simulation, it may be
more difficult to meet specifications without them.
Note, however, some signal quality specifications
require that the diodes be removed from the input
model. The series resistors (RS) are a part of the
diode model. Remove these when removing the
diodes from the input model.
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