Chapter 10.

AMD 29K Dependent Features

10.1. Options

as

has no additional command line options for the AMD 29K family.

10.2. Syntax

10.2.1. Macros

The macro syntax used on the AMD 29K is like that described in the AMD 29K Family Macro

Assembler Specification. Normal

as

macros should still work.

10.2.2. Special Characters

;

is the line comment character.

The character

?

is permitted in identifiers (but may not begin an identifier).

10.2.3. Register Names

General purpose registers are represented by predefined symbols of the form

GRnnn

(for global regis 

ters) or

LRnnn

(for local registers), where

nnn

represents a number between

0

and

127

, written with

no leading zeros. The leading letters may be in either upper or lower case; for example,

gr13

and

LR7

are both valid register names.

You may also refer to general purpose registers by specifying the register number as the result of an

expression (prefixed with

%%

to flag the expression as a register number):

%%expression

  where

expression

must be an absolute expression evaluating to a number between

0

and

255

. The

range [0, 127] refers to global registers, and the range [128, 255] to local registers.

In addition,

as

understands the following protected special purpose register names for the AMD 29K

family:

vab

chd

pc0

ops

chc

pc1

cps

rbp

pc2

cfg

tmc

mmu

cha

tmr

lru

These unprotected special purpose register names are also recognized:

ipc

alu

fpe

ipa

bp

inte