IPT-C2H-NIOS Altera, IPT-C2H-NIOS Datasheet - Page 71

• 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

Example 3–26. Data Dependency
int foo(int a, int b, int c)
{
}
Altera Corporation
November 2009
int x = a * b;
int y = b * c;
int z = x + y;
return z;
hardware. After the C2H Compiler creates the functional units, it
generates a hierarchy of state machines to control the operation and
interaction of these units.
The C2H Compiler generates a distinct state machine for each of the
following:
■
■
■
The states comprise a sequence of stages that compute the results of the C
function. The C2H Compiler assigns each operation to a state of the state
machine. An arbitrary number of operations can execute during one state,
allowing multiple operations to execute in parallel. Generally, the time for
one state to execute equates to one clock cycle, although certain
conditions cause stalls in the state machine's progression through states.
Data Dependencies
Scheduling of assignments within an accelerator is based on the data
dependencies between the assignments. If assignment B depends on a
value calculated in assignment A, then B cannot execute until A has
completed. If two or more assignments are not dependent on each other,
they can be scheduled in parallel.
One way to illustrate data dependencies is through a dependency graph.
For each expression, arrows in a dependency graph represent where the
inputs come from, and where the output is used. These arrows illustrate
the flow of data through this function.
Figure 3–12
Accelerated function (top level)
Loop
Subfunction
shows the dependency graph for
9.1
C-to-Hardware Mapping Reference
Nios II C2H Compiler User Guide
Example
3–26.
3–31