Altera Floating-Point User Manual
Page 77
ALTFP_EXP Design Example: Understanding the Simulation Results
The simulation waveform in this design example is not shown in its entirety. Run the design example files
in the ModelSim-Altera software to see the complete simulation waveforms.
These figures show the expected simulation results in the ModelSim-Altera software.
Figure 9-1: ALTFP_EXP ModelSim Simulation Waveform (Input Data)
Figure 9-2: ALTFP_EXP ModelSim Simulation Waveform (Output Data)
This design example implements a floating-point exponential for the single-precision format numbers.
The optional input ports (
clk_en
and
aclr
) and all four exception handling output ports (
nan
,
overflow
,
underflow
, and
zero
) are enabled.
For single-precision format numbers, the latency is fixed at 17 clock cycles. Therefore, every exponential
operation outputs the results 17 clock cycles later.
Table 9-3: Summary of Input Values and Corresponding Outputs
This table lists the inputs and corresponding outputs obtained from the simulation in the waveforms.
Time
Event
0 ns, start-up
data[]
value: 1A03 568Ch
Output value: An undefined value is seen on the
result[]
port, which is ignored. All
values seen on the output port before the 17th clock cycle are merely due to the
behavior of the system during start-up and should be disregarded.
UG-01058
2014.12.19
ALTFP_EXP Design Example: Understanding the Simulation Results
9-3
ALTFP_EXP IP Core
Altera Corporation