SW006012 Microchip Technology, SW006012 Datasheet - Page 23

• Manufacturer Part Number: SW006012
• Description: C COMPILER FOR DSPIC30F FAMILY
• Manufacturer: Microchip Technology
• Type: MPLAB® C30 Compilerr
• Series: PIC24 & DsPICr

Specifications of SW006012

• Supported Families: PIC24, DsPIC30F And DsPIC33F
• Core Architecture: PIC, DsPIC
• Kit Contents: Software And Docs
• Mcu Supported Families: PIC24 MCUs And DsPIC DSCs
• Tool Type: Compiler
• Processor Series: PIC24, dsPIC
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: dsPIC30F
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

© 2007 Microchip Technology Inc.
Differences Between MPLAB C30 and ANSI C
sfr (address)
The sfr attribute tells the compiler that the variable is an SFR and also specifies the
runtime address of the variable, using the address parameter.
extern volatile int
The use of the extern specifier is required in order to not produce an error.
space (space)
Normally, the compiler allocates variables in general data space. The space attribute
can be used to direct the compiler to allocate a variable in specific memory spaces.
Memory spaces are discussed further in Section 4.6 “Memory Spaces”. The
following arguments to the space attribute are accepted:
Note:
data
Allocate the variable in general data space. Variables in general data space can
be accessed using ordinary C statements. This is the default allocation.
xmemory - dsPIC30F/33F DSCs only
Allocate the variable in X data space. Variables in X data space can be accessed
using ordinary C statements. An example of xmemory space allocation is:
int x[32] __attribute__ ((space(xmemory)));
ymemory - dsPIC30F/33F DSCs only
Allocate the variable in Y data space. Variables in Y data space can be accessed
using ordinary C statements. An example of ymemory space allocation is:
int y[32] __attribute__ ((space(ymemory)));
prog
Allocate the variable in program space, in a section designated for executable
code. Variables in program space can not be accessed using ordinary C
statements. They must be explicitly accessed by the programmer, usually using
table-access inline assembly instructions, or using the program space visibility
window.
auto_psv
Allocate the variable in program space, in a compiler-managed section
designated for automatic program space visibility window access. Variables in
auto_psv space can be read (but not written) using ordinary C statements, and
are subject to a maximum of 32K total space allocated. When specifying
space(auto_psv), it is not possible to assign a section name using the sec-
tion attribute; any section name will be ignored with a warning. A variable in the
auto_psv space cannot be placed at a specific address or given a reverse
alignment.
Note:
By convention, the sfr attribute is used only in processor header files. To
define a general user variable at a specific address use the address
attribute in conjunction with near or far to specify the correct addressing
mode.
Variables placed in the auto_psv section are not loaded into data
memory at startup. This attribute may be useful for reducing RAM
usage.
__
attribute
__
((sfr(0x200)))u1mod;
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