Evaluation Kit User Manual
EV9000
2001 Consumer Microcircuits Limited
31
UM9000/2
4.5.3.2.2 EV9000 Controls
Description Screen
Control
The "Xtal MHz" baud rate calculator uses
the crystal frequency, entered in MHz, and
the CKDIV parameter of the Control
Register to calculate and display the
resultant baud rate which will be obtained.
Note that the CMX969, FX919B and
FX929B modems carry two bits per baud.
As a result, the bit rate is twice the
calculated baud rate. (In this case, the
baud rate is stated in symbols per second
or s/s.) The CMX909B modem carries one
bit per baud, therefore its baud and bit
rates are equal.
Figure 19: Xtal MHz Baud Rate Calculator
Control
Noise selectors apply to the channel A
receive path (see Figure 6). Only one
selection may be active at a time. If no
noise injection is desired, simply
disconnect any wires connected to
motherboard connectors NSA1 and NSA2.
Figure 20: Channel A, Noise Control
DC Offset selectors apply to the Channel A
receive path (see Figure 6). Only one
selection may be active at a time. Note
that the Zero selection can introduce an
offset depending upon motherboard
hardware adjustment.
Figure 21: Channel A, DC Offset
Bit Error Rate Test Length selects the
number of bits (in exponential notation) to
be transferred during a BER test. This
selection has a dramatic affect on the time
required to perform a BER test with the
greater number of bits taking more time.
Longer tests produce more accurate
results.
Figure 22: BER Test Length
Random sequence is the number of bits
produced by the pseudorandom sequence
generator which is employed to generate
nearly random data streams used in tests.
It is not perfectly random because the bits
are produced in a repeating pattern. The
random sequence length is the number of
bits produced before the pattern repeats.
The larger the random sequence value, the
more random the produced bit pattern.
Figure 23: Rand seq
Table 16: EV9000 Controls
4.5.3.2.3 Test Area Controls