Signals, Signals -4 – Altera Floating-Point User Manual
Page 96

Time
Event
102.5 ns
Output value: FF80 0000h
The natural logarithm of zero is negative infinity.
5 ns
data[]
value: 8000 0000h
This is a negative number.
107.5 ns
Output value: FFC0 0000h
Exception handling ports:
nan
asserts
The natural logarithm of a negative value is invalid. Therefore, the output produced
is a NaN.
30 ns
data[]
value: 0040 0000h
The is a denormal value.
132.5 ns
Output value: FF80 0000h
As denormal numbers are not supported, the input is forced to zero before going
through the logarithm function. The natural logarithm of zero is negative infinity.
45 ns
data[]
value: 0080 0000h
This is the smallest valid input. All the input bits are 0 except the LSB of the
exponent field.
147.5 ns
Output value: C2AE AC50h
60 ns
data[]
value: 3F80 0000h
The input value 3F80 0000h is equivalent to the actual value,
1.0 × 20 = 1.
152.5 ns
Output value: 0000 0000h
Exception handling ports:
zero
asserts
Since In 1 results in zero, it produces an output of zero.
Signals
12-4
Signals
UG-01058
2014.12.19
Altera Corporation
ALTFP_LOG