IPT-C2H-NIOS Altera, IPT-C2H-NIOS Datasheet - Page 43

• Manufacturer Part Number: IPT-C2H-NIOS
• Description: C2H COMPILER FOR NIOS II
• Manufacturer: Altera
• Series: Nios®IIr
• Type: Nios IIr

Specifications of IPT-C2H-NIOS

• Function: C to Hardware Compiler
• License: Initial License
• Software Application: IP CORE, NIOS Processor And Functions
• Core Architecture: FPGA
• Core Sub-architecture: Cyclone
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: Not applicable / Not applicable

Altera Corporation
November 2009
There are two types of exceptions to this rule:
■
■
The following sections discuss these exceptions.
Unregistered Operations and Assignments
Certain logical and bit-wise operations involving constants are trivial and
require no logic. In hardware, they are performed simply by
manipulating wires.
conditions. If an assignment consists solely of such operations, then its
result is not registered.
The following assignment is an example of a zero logic-element
operation.
The C2H Compiler generates no register for the variable masked_data,
because its value is represented simply by concatenating 12 bits of zeroes
with the lower 20 bits of data_in.
Additional examples of unregistered assignments:
Table 3–2. Operators That Can Result in Unregistered Assignments
Operator
Assignments that require zero logic elements in hardware
Assignments that use multiple registers to pipeline complex
arithmetic operations
int masked_data = data_in & 0x000fffff;
shift_by_constant
or_with_constant
invert_shift_and_consts = (~data_in & 0xff) << 8;
>>
<<
&
|
^
~
)
Right bit-wise shift
Left bit-wise shift
bit-wise AND
bit-wise inclusive OR
bit-wise exclusive OR
bit-wise inversion
Type cast
Description
Table 3–2
9.1
lists the applicable operators and
Right-hand side is constant
Either operand is constant
Right-hand side is constant
Either operand is constant
Either operand is constant
Right-hand side is unregistered
Right-hand side is unregistered
= data_in << 3;
= data_in | 0xf0f0f0f0;
C-to-Hardware Mapping Reference
Nios II C2H Compiler User Guide
Required Condition
3–3