;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;
|
;
|
; Filename: wdt.S
|
; Filename: wdt.S
|
;
|
;
|
; Project: Zip CPU -- a small, lightweight, RISC CPU soft core
|
; Project: Zip CPU -- a small, lightweight, RISC CPU soft core
|
;
|
;
|
; Purpose: Test to see whether or not the watchdog timer works. We'll
|
; Purpose: Test to see whether or not the watchdog timer works. We'll
|
; start the watchdog, clear a register, then write as many times
|
; start the watchdog, clear a register, then write as many times
|
; as we can to memory before the watchdog kicks in.
|
; as we can to memory before the watchdog kicks in.
|
;
|
;
|
; Creator: Dan Gisselquist, Ph.D.
|
; Creator: Dan Gisselquist, Ph.D.
|
; Gisselquist Tecnology, LLC
|
; Gisselquist Tecnology, LLC
|
;
|
;
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;
|
;
|
; Copyright (C) 2015, Gisselquist Technology, LLC
|
; Copyright (C) 2015, Gisselquist Technology, LLC
|
;
|
;
|
; This program is free software (firmware): you can redistribute it and/or
|
; This program is free software (firmware): you can redistribute it and/or
|
; modify it under the terms of the GNU General Public License as published
|
; modify it under the terms of the GNU General Public License as published
|
; by the Free Software Foundation, either version 3 of the License, or (at
|
; by the Free Software Foundation, either version 3 of the License, or (at
|
; your option) any later version.
|
; your option) any later version.
|
;
|
;
|
; This program is distributed in the hope that it will be useful, but WITHOUT
|
; This program is distributed in the hope that it will be useful, but WITHOUT
|
; ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
|
; ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
|
; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
; for more details.
|
; for more details.
|
;
|
;
|
; License: GPL, v3, as defined and found on www.gnu.org,
|
; License: GPL, v3, as defined and found on www.gnu.org,
|
; http://www.gnu.org/licenses/gpl.html
|
; http://www.gnu.org/licenses/gpl.html
|
;
|
;
|
;
|
;
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;
|
;
|
; Registers:
|
; Registers:
|
; R12 Peripheral base
|
; R12 Peripheral base
|
; R11 Address of our one memory variable
|
; R11 Address of our one memory variable
|
;
|
;
|
start:
|
start:
|
CLR R12 ; Get the address of our peripheral base
|
CLR R12 ; Get the address of our peripheral base
|
LDIHI $c000h,R12
|
LDIHI $c000h,R12
|
MOV $1+PC,R11 ; Get a memory address for a variable
|
MOV $1+PC,R11 ; Get a memory address for a variable
|
BRA $1
|
BRA $1
|
.DAT 0
|
.DAT 0
|
LDI $800h,R0 ; Start the watchdog timer
|
LDI $-1,R0 ; Start the watchdog timer
|
STO R0,$1(R12)
|
STO R0,$1(R12)
|
LSR $1,R0
|
LSR $1,R0
|
STO R0,$4(R12)
|
STO R0,$4(R12)
|
LSR $1,R0
|
LSR $1,R0
|
STO R0,$5(R12)
|
STO R0,$5(R12)
|
LSR $1,R0
|
LSR $1,R0
|
STO R0,$6(R12)
|
STO R0,$6(R12)
|
;
|
;
|
CLR R0
|
CLR R0
|
loop:
|
loop:
|
ADD $1,R0
|
ADD $1,R0
|
LOD (R11),R1
|
LOD (R11),R1
|
CMP R0,R1
|
CMP R0,R1
|
STO.LT R0,(R11)
|
STO.LT R0,(R11)
|
TST R0
|
TST R0
|
BLT $2
|
BLT $2
|
BRA $-7
|
BRA $-7
|
|
|
HALT
|
HALT
|
|
|
