IPT-C2H-NIOS Altera, IPT-C2H-NIOS Datasheet - Page 66

• 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

Memory Accesses
Example 3–17. Pragma Specifying Arbitration Share
#pragma altera_accelerate connect_variable myfunc/x to sdram \
3–26
Nios II C2H Compiler User Guide
arbitration_share 16
f
Example 3–17
module named sdram with an arbitration share of 16.
Specifying Flow Control
Avalon-MM transfers with flow control force a master port to obey flow
control signals controlled by a slave port. For example, a slave FIFO might
assert flow control signals to prevent write transfers when the FIFO
memory is full. The C2H Compiler provides a flow control pragma which
enables flow control for all master ports related to a specific pointer
variable.
The flow control pragma is defined as follows:
The flow control pragma must be placed in the same file as the function
to be accelerated, but outside the function. <function name> and
<variable name> are the exact names of the accelerated function and the
pointer variable.
For details about Avalon-MM flow control, refer to the
Mapped Interface
Array Subscript Operator
The C2H Compiler converts array subscript operations to equivalent
pointer dereferences, and then translates the pointer dereferences to
hardware. An array is a pointer with abstractions of length and
dimension. The value of an array type is defined to be a pointer to its first
element. The C language specification defines the array subscript
operator as follows:
By this definition, any array subscripting (indexing) operation can be
expressed in terms of an indirection (pointer dereference) operation.
The definition of the subscript operator [] is that E1[E2] is identical to
(*((E1)+(E2))).
#pragma altera_accelerate \
enable_flow_control_for_pointer \
<function name>/<variable name>
connects the variable x in function myfunc to the memory
Specification.
9.1
Altera Corporation
Avalon Memory-
November 2009