Module Call-In, Call-Out Example; Call-Out Dispatch Table And Module Size - Motorola M68060 User Manual

MC68060 Software Package
TABLE MUST IMMEDIATELY
PRECEDE THE THE ENTRY-
CALLING ROUTINE
bra _top+func_offset
next instruction
_done:
Table C-1 shows the code size of each module.
Table C-1. Call-Out Dispatch Table and Module Size
Module Name
Unimplemented Integer
Unimplemented Integer Instruction Library
Full Floating-Point Kernel
Floating-Point Library
Partial Floating-Point Kernel
C.2 UNIMPLEMENTED INTEGER INSTRUCTIONS
The MC68060 left some low-use integer instructions unimplemented to streamline internal
operations. This results in overall system performance improvement at the expense of soft-
ware emulation of the unimplemented integer instructions. The M68060SP provides user
object-code compatibility by providing the code needed to emulate these instructions via the
unimplemented integer instruction exception. The M68060SP also provides a software
C-4
_top
CALL-OUT DISPATCH
L1:
L2:
POINT SECTION
ENTRY-POINT DISPATCH SECTION
MODULE FUNCTIONS
ARE FIXED OFFSETS
FROM THE LABEL _top
_top+func_offset
f1: Actual func code
Figure C-3. Module Call-In, Call-Out Example
Call-Out Dispatch
M68060 USER'S MANUAL
MODULE
CALL-OUT DISPATCH TABLE
_call_out - _top
_done - _top
bra f1
CODE SECTION
_call_out: call_out code here
*Do a call-out
lea _top,A0
add.1 L1,A0
jsr (a0)
next instruction
lea _top,A0
add.1 L2,A0
jmp (a0)
Entry-Point + Code
Table Size
Section Size
128 bytes 8K-128 bytes
0 bytes 4K bytes
128 bytes 56K-128 bytes
0 bytes 34K bytes
128 bytes 35K-128 bytes
THE ENTRY-POINT AND CODE
SECTIONS ARE INTHE
PSEUDO-ASSEMBLY FILE
OPERATING SYSTEM-SUPPLIED CODE
rts
Total Module
Size
8K bytes
4K bytes
56K bytes
34K bytes
35K bytes
MOTOROLA