Altera DE1-SoC, Manual, Page: 7 / 45

DE1-S
O
C C
OMPUTER
S
YSTEM WITH
N
IOS
II
For Quartus II 15.0
/********************************************************************************
* This program demonstrates the use of parallel ports in the DE1-SoC Computer:
*
1. displays the SW switch values on the red LEDR
* 2. displays a rotating pattern on the HEX displays
* 3. if KEY[3..0] is pressed, uses the SW switches as the pattern
********************************************************************************/
. text /* executable code follows */
.
global
_start
_start:
/* initialize base addresses of parallel ports */
movia r15, 0xFF200040 /* SW slider switch base address */
movia r16, 0xFF200000 /* red LED base address */
movia r17, 0xFF200050 /* pushbutton KEY base address */
movia r20, 0xFF200020 /* HEX3_HEX0 base address */
movia r19, HEX_bits
ldwio r6, 0(r19) /* load pattern for HEX displays */
DO_DISPLAY:
ldwio r4, 0(r15) /* load input from slider switches */
stwio r4, 0(r16) /* write to red LEDs */
ldwio r5, 0(r17) /* load input from pushbuttons */
beq r5, r0, NO_BUTTON
mov r6, r4 /* copy SW switch values onto HEX displays */
WAIT:
ldwio r5, 0(r17) /* load input from pushbuttons */
bne r5, r0, WAIT /* wait for button release */
NO_BUTTON:
stwio r6, 0(r20) /* store to HEX3 ... HEX0 */
roli r6, r6, 1 /* rotate the displayed pattern */
movia
r7, 500000 /* delay counter */
DELAY:
subi r7, r7, 1
bne
r7, r0, DELAY
br DO_DISPLAY
.
data
/* data follows */
HEX_bits:
. word 0x0000000F
.
end
Figure 8. An example of assembly language code that uses parallel ports.
Altera Corporation - University Program
2015
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