IPTR-C2H-NIOS Altera, IPTR-C2H-NIOS Datasheet - Page 56

• Manufacturer Part Number: IPTR-C2H-NIOS
• Description: IP CORE Renewal Of IPT-C2H-NIOS
• Manufacturer: Altera

Specifications of IPTR-C2H-NIOS

• Software Application: IP CORE, NIOS Processor And Functions
• Core Architecture: Nios II
• Features: ANSI C Compliance, Straightforward C-to-Hardware Mapping, Reporting Of Generated Results
• Core Sub-architecture: Cyclone
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na

Memory Accesses
Example 3–8. C Statements that Generate Avalon-MM master ports
*my_ptr = 8;
data_in = *src;
dst[index] = data_out;
pixel = pixel_array[i][j];
buffer.input = 0x80000400;
current = s->next;
3–16
Nios II C2H Compiler User Guide
f
behavior of a C function accessing memory is the same, regardless of
whether the function is implemented as hardware logic or software
instructions.
For more information on SOPC Builder, Avalon interfaces, and how
SOPC Builder generates system interconnect fabric, refer to the
Quartus II Handbook, volume 4: SOPC Builder
Mapped Interface
In order to maximize bandwidth, the C2H Compiler creates a master port
on the accelerator for every C operator that accesses external memory.
Multiple master ports allow the accelerator to read and write data to an
unlimited number of locations simultaneously, thereby reducing the
bandwidth limitations inherent in a CPU with a single data master port.
In some cases, the C2H Compiler can determine that master ports can be
shared between several external memory operations without sacrificing
performance. However, as a general rule, an Avalon-MM master port is
created for each of the following:
■
■
■
■
Example 3–8
port in hardware.
The following sections describe each case in detail.
Indirection Operator (Pointer Dereference)
The indirection operator (*) is the fundamental expression of
dereferencing and indirection. This section describes how the
C2H Compiler handles pointer dereferencing.
Pointer dereference (* operator)
Index into an array ([ operator)
Index into a struct or union (. or -> operator)
Usage of a global or static variable
demonstrates various lines of code that generate a master
Specification.
9.1
and the
Avalon Memory-
Altera Corporation
November 2009