07.03.2014 Views

Introduction.

Introduction.

Introduction.

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Workshop PG5<br />

Resources<br />

Symbol names:<br />

Symbol names are names which can be assigned to elements in the PCD (inputs,<br />

outputs, flags, registers, COBs etc). Symbol names can be up to 80 characters<br />

long and are not case sensitive unless they contain foreign characters.<br />

MotorOn is the same as MOTORON, but GRÜN is not the same as grün.<br />

Symbols have to start with a letter ( a-z, A-Z) a number won't be accepted.<br />

Within the symbol you can mix numbers, letters and underlines "_" as you<br />

wish. You cannot have a space in a symbol name.<br />

Reserved Words cannot be used as symbol names.<br />

Reserved Words:<br />

The following words are reserved, and cannot be used as symbol names:<br />

♦ Assembler declarators, e.g. PUBL, EXTN, EQU, DEF, LEQU, LDEF,<br />

MACRO, ENDM, EXITM etc.<br />

♦ Medium control codes and data types (I, O, F, R, C, T, K, M, COB, FB,<br />

TEXT, X, SEMA, DB).<br />

♦ MOV instruction special codes (N, Q, B, W, L, D).<br />

♦ Condition codes (H, L, P, N, Z, E).<br />

♦ All instruction mnemonics.<br />

♦ Pre-defined symbols.<br />

♦ Internal symbols used for automatic resource allocation, which begin with<br />

underscores, e.g.<br />

______TEXT, _________F.<br />

Internal __CSTART__ symbol, used for $$ assignments.<br />

© Saia-Burgess Controls Ltd. Page 3-26

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!