Altera DE1-SoC - Page 4

DE1-SOC COMPUTER SYSTEM WITH NIOS II For Quartus II 15.0
Some of the parallel ports in the DE1-SoC Computer have registers at addresses Base + 8 and Base + C, as indicated
in Figure 2. These registers are discussed in Section 3.
2.4.1 Red LED Parallel Port
The red lights LEDR
9−0
on the DE1-SoC board are driven by an output parallel port, as illustrated in Figure 3. The
port contains a 10-bit write-only Data register, which has the address 0xFF200000. This register can be written
using word accesses, and the upper bits not used in the registers are ignored.
0xFF200000
LEDR
0
LEDR
9
Address
031 910
. . .Unused
Data register
Figure 3. Output parallel port for LEDR.
2.4.2 7-Segment Displays Parallel Port
There are two parallel ports connected to the 7-segment displays on the DE1-SoC board, each of which comprises
a 32-bit write-only Data register. As indicated in Figure 4, the register at address 0xFF200020 drives digits HEX3
to HEX0, and the register at address 0xFF200030 drives digits HEX5 and HEX4. Data can be written into these
two registers by using word operations. This data directly controls the segments of each display, according to the bit
locations given in Figure 4. The locations of segments 6 to 0 in each seven-segment display on the DE1-SoC board
is illustrated on the right side of the figure.
0xFF200020
...
HEX0
6-0
...
HEX1
6-0
...
HEX3
6-0
Address
076815 142431 30
0xFF200030
...
HEX2
6-0
1623 22
...
HEX4
6-0
...
HEX5
6-0
076815 142431 30 1623 22
Data register
Data register
0
1
2
3
4
5
6
Segments
Unused
Figure 4. Bit locations for the 7-segment displays parallel ports.
4 Altera Corporation - University Program
2015