SW500009 Microchip Technology, SW500009 Datasheet - Page 155

• 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

Linker and Utilities
5.13.1 Checksum Specifications
If you are generating a HEX file output, please refer to the hexmate section
checksums. For OBJTOHEX, the checksum specification allows automated checksum calculation and
takes the form of several lines, each line describing one checksum. The syntax of a checksum line
is:
All of addr1, addr2, where1, where2 and offset are hex numbers, without the usual H suffix.
Such a specification says that the bytes at addr1 through to addr2 inclusive should be summed
and the sum placed in the locations where1 through where2 inclusive. For an 8 bit checksum
these two addresses should be the same. For a checksum stored low byte first, where1 should be less
than where2, and vice versa. The +offset is optional, but if supplied, the value offset will be used
to initialise the checksum. Otherwise it is initialised to zero. For example:
This will sum the bytes in 5 through 1FFFH inclusive, then add 1FFFH to the sum. The 16 bit
checksum will be placed in locations 3 and 4, low byte in 3. The checksum is initialised with 1FFFH
to provide protection against an all zero ROM, or a ROM misplaced in memory. A run time check of
this checksum would add the last address of the ROM being checksummed into the checksum. For
the ROM in question, this should be 1FFFH. The initialization value may, however, be used in any
desired fashion.
5.14 Cref
The cross reference list utility CREF is used to format raw cross-reference information produced by
the compiler or the assembler into a sorted listing. A raw cross-reference file is produced with the
--CR option to the compiler. The assembler will generate a raw cross-reference file with a -C option
(most assemblers) or by using an OPT CRE directive (6800 series assemblers) or a XREF control line
(PIC assembler). The general form of the CREF command is:
where options is zero or more options as described below and files is one or more raw cross-
reference files. CREF takes the options listed in Table 5.5.
Each option is described in more detail in the following paragraphs.
addr1-addr2 where1-where2 +offset
0005-1FFF 3-4 +1FFF
cref options files
5.16
for calculating
Cref
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