OpenCores
URL https://opencores.org/ocsvn/zipcpu/zipcpu/trunk

Subversion Repositories zipcpu

[/] [zipcpu/] [trunk/] [bench/] [asm/] [nullpc.s] - Blame information for rev 93

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 74 dgisselq
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
2
;
3
; Filename:     nullpc.s
4
;
5
; Project:      Zip CPU -- a small, lightweight, RISC CPU soft core
6
;
7
; Purpose:      A quick test of whether or not the prefetch shuts down and
8
;               idles properly when given an invalid (NULL) address.  This is
9
;       intended to be run in the simulator (zippy_tb), as I don't know how I
10
;       would verify operation on a real device.
11
;
12
; Creator:      Dan Gisselquist, Ph.D.
13
;               Gisselquist Technology, LLC
14
;
15
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
16
;
17
; Copyright (C) 2015, Gisselquist Technology, LLC
18
;
19
; This program is free software (firmware): you can redistribute it and/or
20
; modify it under the terms of  the GNU General Public License as published
21
; by the Free Software Foundation, either version 3 of the License, or (at
22
; your option) any later version.
23
;
24
; This program is distributed in the hope that it will be useful, but WITHOUT
25
; ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
26
; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
27
; for more details.
28
;
29
; License:      GPL, v3, as defined and found on www.gnu.org,
30
;               http://www.gnu.org/licenses/gpl.html
31
;
32
;
33
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
34
;
35
start:
36
        CLR     R0
37
        CLR     R1
38
        CLR     R2
39
        CLR     R3
40
        CLR     R4
41
        MOV     R0,uR0
42
        MOV     R0,uR1
43
        MOV     R0,uR2
44
        MOV     R0,uR3
45
        MOV     R0,uR4
46
        MOV     user_start(PC),uPC
47
        MOV     R0,uCC
48
        RTU
49
        MOV     uCC,R0
50
        TST     0x100,R0
51
        BNZ     user_test_worked
52
        ; We could do a BUSY.Z, but then the simulator wouldn't have
53
        ; picked up our stop condition
54
        BUSY
55
user_test_worked:
56
        MOV     user_dive_test(PC),uPC
57
        RTU
58
        MOV     uCC,R0
59
        TST     0x0800,R0
60
        BRA     user_dive_worked
61
        BUSY
62
user_dive_worked:
63
        ; Finally, let's test whether or not a null address from supervisor
64
        ; mode halts the CPU as desired.
65
        JMP     R1
66
        NOOP
67
        NOOP
68
        ; HALT = success.  However, if we halt here we certainly don't have
69
        ; a success.  Hence, signal a test failure by calling a busy instruction
70
        BUSY
71
 
72
; Let's see if jumping to a null address creates the exception we want
73
user_start:
74
        JMP     R1
75
        NOOP
76
        NOOP
77
 
78
; How about divide by zero?
79
user_dive_test:
80
        LDI     25,R0
81
        CLR     R1
82
        CLR     R2
83
        DIVS    R1,R0
84
        ADD     1,R2
85
        ADD     1,R2
86
        ADD     1,R2
87
        ADD     1,R2
88
        ADD     1,R2
89
        BUSY

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.