Table of Contents
Advertisement
, CORE INSTRUCTIONS
5.9 SOFTWARE TRAPS
trap isrc
1 ni, isrc2, idest
Generate trap with IT set in psr
intovr
IF OF in epsr
=
1
THEN generate trap with IT set in psr
FI
(Software trap)
(Software trap on integer overflow)
These instructions generate the instruction trap, as described in Chapter 7.
The
trap
instruction can be used to implement supervisor calls and code breakpoints.
The ides! should be zero, because its contents are undefined after the operation. The
isrclni
and isrc2 fields can be used to encode the type of trap.
The
intovr
instruction generates an instruction trap if the OF bit (overflow flag) of
epsr
is set. It is used to test for integer overflow after the instructions
adds, addu, subs,
and
subu.
5-13
Advertisement
Table of Contents
