SW006012 Microchip Technology, SW006012 Datasheet - Page 84

• 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

MPLAB
4.13
DS51284F-page 78
REGISTER CONVENTIONS
®
C30 User’s Guide
4.12.3
The compiler arranges for registers W8-W15 to be preserved across ordinary function
calls. Registers W0-W7 are available as scratch registers. For interrupt functions, the
compiler arranges for all necessary registers to be preserved, namely W0-W15 and
RCOUNT.
Specific registers play specific roles in the C runtime environment. Register variables
use one or more working registers, as shown in Table 4-4.
TABLE 4-4:
char, signed char, unsigned char W0-W13, and W14 if not used as a Frame
short, signed short, unsigned
short
int, signed int,unsigned int
void * (or any pointer)
long, signed long, unsigned long A pair of contiguous registers, the first of which
long long, signed long long,
unsigned long long
float
double*
long double
* double is equivalent to long double if -fno-short-double is used.
Preserving Registers Across Function Calls
REGISTER CONVENTIONS
Variable
Pointer.
W0-W13, and W14 if not used as a Frame
Pointer.
W0-W13, and W14 if not used as a Frame
Pointer.
W0-W13, and W14 if not used as a Frame
Pointer.
is a register from the set {W0, W2, W4, W6, W8,
W10, W12}. The lower-numbered register
contains the least significant 16-bits of the value.
A quadruplet of contiguous registers, the first of
which is a register from the set {W0, W4, W8}.
The lower-numbered register contains the least
significant 16-bits of the value. Successively
higher-numbered registers contain successively
more significant bits.
A pair of contiguous registers, the first of which
is a register from the set {W0, W2, W4, W6, W8,
W10, W12}. The lower-numbered register
contains the least significant 16-bits of the
significant.
A pair of contiguous registers, the first of which
is a register from the set {W0, W2, W4, W6, W8,
W10, W12}. The lower-numbered register
contains the least significant 16-bits of the
significant.
A quadruplet of contiguous registers, the first of
which is a register from the set {W0, W4, W8}.
The lower-numbered register contains the least
significant 16-bits of the significant.
Working Register
© 2007 Microchip Technology Inc.