SW500009 Microchip Technology, SW500009 Datasheet - Page 54

• Manufacturer Part Number: SW500009
• Description: HI-TECH FOR DSPIC/PIC24
• Manufacturer: Microchip Technology
• Type: Compilerr
• Series: PIC24 & DsPICr

Specifications of SW500009

• Supported Families: PIC24
• Core Architecture: PIC, DsPIC
• Software Edition: Standard
• Kit Contents: Software And Docs
• Tool Type: Compiler
• Mcu Supported Families: PIC24 MCUs And DsPIC DSCs
• Lead Free Status / RoHS Status: Not applicable / RoHS Compliant
• For Use With/related Products: DSPIC3X/PIC24
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 025; 778-1003; 778-1003

Files
3.3.4.2 Clearing the Bss Psects
The ANSI standard dictates that those non-auto objects which are not initialized must be cleared
before execution of the program begins. The compiler does this by grouping all such uninitialized
objects into a bss psect. This psect is then cleared as a block by the runtime startup code.
used in IBM systems back in the days when computers were coal-fired. The continued usage of this
term is still appropriate.
For example:
unpredictable when the program begins execution.
with persistent, see Section 3.4.9.1. Such variables are linked at a different area of memory and are
not altered by the runtime startup code in anyway.
3.3.4.3 Linking in the C Libraries
By default, a set of libraries are automatically passed to the linker to be linked in with user’s program.
The libraries can be omitted by disabling the clib suboption of --RUNTIME. For example:
source files to allow calls to library routines. This suboption may be useful if alternative library or
source files are available and you wish to ensure that no HI-TECH C library routines are present in
the final output.
function was called by the C code. These calls perform such operations as division or floating-point
arithmetic. If the C libraries have been excluded from the code output, these implicit library calls
will also require substitutes.
3.3.4.4 The powerup Routine
Some hardware configurations require special initialization, often within the first few cycles of ex-
ecution after reset. To achieve this there is a hook to the reset vector provided via the powerup
routine. This is a user-supplied assembler module that will be executed immediately on reset. Often
this can be embedded in a C module as embedded assembler code. A “dummy” powerup routine is
included in the file powerup.as. The file can be copied, modified and included into your project.
No special linking options or jumps to the powerup routine are required, the compiler will detect if
40
The abbreviation "bss" stands for Block Started by Symbol and was an assembler pseudo-op
The name of the bss psect is rbss.
The block clear of the bss psect may be omitted by disabling the clear suboption of --RUNTIME.
–RUNTIME=default,-clear
With this part of the runtime startup code absent, the contents of uninitialized variables will be
Variables whose contents should be preserved over a reset, or even power off, should be qualified
–RUNTIME=default,-clib
With this part of the runtime startup code absent, the user must provide alternative library or
Some C statements produce assembler code that call library routines even though no library
C Language Features