DE1-SOC COMPUTER SYSTEM WITH NIOS II For Quartus II 15.0
stw r8, 16(sp)
stw r10, 20(sp)
stw r20, 24(sp)
stw r21, 28(sp)
stw r22, 32(sp)
stw r23, 36(sp)
movia r10, 0xFF202000 /* interval timer base address */
sthio r0, 0(r10) /* clear the interrupt */
movia r20, 0xFF200020 /* HEX3_HEX0 base address */
movia r21, PATTERN /* set up a pointer to the pattern for HEX displays */
movia r22, KEY_PRESSED /* set up a pointer to the key pressed */
movia r23, SHIFT_DIR /* set up a pointer to the shift direction variable */
ldw r6, 0(r21) /* load pattern for HEX displays */
stwio r6, 0(r20) /* store to HEX3 ... HEX0 */
ldw r4, 0(r22) /* check which key has been pressed */
CHK_KEY0:
movi r8, KEY0 /* code to check for KEY1 */
bne r4, r8, CHK_KEY1
movia r20, SLIDER_SWITCH_BASE
ldw r6, 0(r20) /* load a new pattern from the SW switches */
br SHIFT
CHK_KEY1:
movi r8, KEY1 /* code to check for KEY1 */
bne r4, r8, CHK_KEY2
movi r5, RIGHT /* KEY1 sets rotation direction to the right */
stw r5, 0(r23)
br SHIFT
CHK_KEY2:
movi r8, KEY2 /* code to check for KEY2 */
bne r4, r8, CHK_KEY3
movi r5, LEFT /* KEY2 sets rotation direction to the left */
stw r5, 0(r23)
br SHIFT
Figure 18. Interrupt service routine for the interval timer (Part b).
20 Altera Corporation - University Program
2015
To Next Page
Loading...
