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[/] [zipcpu/] [trunk/] [bench/] [asm/] [helloworld.S] - Rev 45
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;
; Filename: helloworld.S
;
; Project: Zip CPU -- a small, lightweight, RISC CPU soft core
;
; Purpose: A test of whether or not we can scroll a message on a
; seven segment display. This depends upon the seven segment
; display driver (not included) being installed at position
; 0x15 in memory. If so, this scrolls the message:
; "HELLO UJorld." across the 4 seven segment display digits.
;
; This test discovered that right shifting by 31 or more did
; not result in zero as desired. It also discovered that the
; .DAT assembly instruction did not function as desired. Both
; bugs were fixed to get this to work.
;
; Creator: Dan Gisselquist, Ph.D.
; Gisselquist Tecnology, LLC
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; Copyright (C) 2015, Gisselquist Technology, LLC
;
; 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
; by the Free Software Foundation, either version 3 of the License, or (at
; your option) any later version.
;
; This program is distributed in the hope that it will be useful, but WITHOUT
; ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
; for more details.
;
; License: GPL, v3, as defined and found on www.gnu.org,
; http://www.gnu.org/licenses/gpl.html
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; Register map
; R12 peripherals
; R11 timer length
; R10 value to clear/reset the PIC
; uR12 = memory
; uR11 = rawsseg
; uR9 = state
; R8 = new value for SSEG
build_supervisor_state:
CLR R12 ; Load a pointer to our peripherals
LDIHI $c000h,R12
LDI $5f5e1h,R11 ; An amount to reset the timer to: 1/4 sec
LSL $6,R11
LDIHI $8010h,R10 ; A value to clear/reset the PIC for timerA ints
LDILO $ffffh,R10
MOV $1+PC,uR12 ; User memory (so this isn't supervisor state..)
BRA $4
.DAT $0x6e9e1c1c ; Raw SSEG for 'HELL'
.DAT $0xfc007c70 ; Raw SSEG for 'O UJ'
.DAT $0x3a0a607b ; Raw SSEG for 'orld.'
.DAT $0x00000000 ; Raw SSEG for ' '
build_user_state:
LDI $15h,R0
MOV R0,uR11
MOV $6+PC,uPC
CLR R0
MOV R0,uR9
repeat:
STO R11,$4(R12) ; Reset the timer
STO R10,(R12) ; Reset the PIC
RTU
BRA $-4
user_task:
MOV R9,R0
LSR $2,R0
ADD R12,R0
LOD (R0),R8 ; Read the left word
MOV R9,R1 ; Rotate it into place
AND $3,R1
LSL $3,R1 ; Multiply by eight
LSL R1,R8 ; Shift words to left by 0,8,16,24 bits
ADD $1,R0 ; Calculate address of next word
CMP $4+R12,R0
SUB.GE $4,R0
LOD (R0),R2 ; Load the next word into a building location
LDI $32,R3
SUB R1,R3
LSR R3,R2
OR R2,R8 ; Put the two together
STO R8,(R11) ; Store the result
ADD $1,R9 ; Increment our state
AND $15,R9
WAIT ; Wait for the next interrupt
BRA $-21 ; Back up to the top to start over
BREAK
BREAK
BREAK
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