SW500008 Microchip Technology, SW500008 Datasheet - Page 65

• Manufacturer Part Number: SW500008
• Description: PICC-18 STD
• Manufacturer: Microchip Technology
• Type: Compilerr
• Series: PIC18r

Specifications of SW500008

• Supported Families: PIC18
• Core Architecture: PIC
• Software Edition: Standard
• Kit Contents: Software And Docs
• Mcu Supported Families: PIC18
• Tool Function: Compiler
• Tool Type: Compiler
• Lead Free Status / RoHS Status: Not applicable / RoHS Compliant
• For Use With/related Products: PIC18 Series
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 015; 778-1001; 778-1001

C Language Features
3.4.10.3 Far Type Qualifier
The far type qualifier is used to place variables of permanent duration into external program space
of the PIC18 for those devices which can support additional memory. Accesses to far variables are
less efficient than accesses to internal variables and extensive accesses to these variables will result
in larger code sizes.
Note that not all devices support extending their memory space in this way and the far qualifier is not
applicable to all PIC18 devices. For those devices that can extend their memory, the address range
where the additional memory will be mapped must first be specified with a –RAM option. For exam-
ple, to map additional data memory from 20000h to 2FFFFh use --RAM=default,+20000-2FFFF.
cases) the --CP=24 command line option will also be required in order to access these variables
correctly.
3.4.11 Bdata Type Qualifier
The bdata type qualifier only has significance when compiling in the small memory model. In
this model all static and extern class variables are placed in the access bank, but this qualifier
specifies that the object is to be placed outside the access bank in the banked data area of the device.
The object then behaves like an unqualified object in large model. This qualifier is useful when the
access bank has overflowed by a small amount as it allows some objects to moved back into the
banked memory and prevents having to revert to the large memory model.
3.4.12 Pointer Types
There are two basic pointer types supported HI-TECH PICC-18 STD: data pointers and function
pointers. Data pointers hold the address of data objects which can be read and/or written by the
program. Function pointers hold the address of an executable routine which can be called indirectly
via the pointer.
PIC18 device, but the const and far pointer types can access the data and program space (typically
ROM, although hardware using devices with an external memory interface may implement any type
of memory in this space).
Here is an example of an unsigned int object placed into the device’s external code space:
Also consider that if the external memory area uses addresses greater than FFFFh (as in most
Of the data pointers, RAM pointers are limited to accessing only the data space (RAM) of the
far unsigned int farvar;
Supported Data Types and Variables
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