ODROID-Magazine-201506

GUZUNTY PI
GCLK3, GND.
Power
I used 3 wires for the IO-Expansion:
Figure 6 – U3 IO-Expansion connector
Figure 5 - Modified PCB
1: VDD_IO (pin 2) is connected to
the CPLD VCCio2 (white wire on C8)
2: P5V0 (pin 8), is connected to the
CPLD board 5V supply
3: GND (pin 7) is connected to
GND on the CPLD board
SPI
I used all 4 wires from the SPI:
SPI_1.CLK must be connected to
(VHDL – sclk) which is CLK2 on the
CLK header
2: SPI_1.CSN must be connected to
(VHDL – sel) which is pin 76 on the P1
header
3: SPI_1.MOSI must be connected
to (VHDL – mosi) which is pin 75 on
the P1 header
4: SPI_1.MISO must be connected
to (VHDL – miso) which is pin 74 on
the P1 header
I could just as easily have mapped
VHDL – miso to pin 73 on the CPLD
if I felt that it was a better fit. All of the
mapping is done in Quartus2, in either
the Pin Planner (easiest), or the Assignment
Editor.
UART
I only used two signals from the
UART header, since I already had GND
via the 5V power connection, leaving
the other signals open:
Figure 7 - U3 SPI connector
1: TTA_RXD must be connected to
(VHDL - to_u3_rx), which is pin 100
on the P4 header
2: TTA_TXD must be connected to
(VHDL - from_u3_tx), which is pin 99
on the P4 header
My 3.3V USB to serial adapter used
4 connections:
1: GND from the ODROID
2: 5V from the ODROID
3: USB TX must be connected to
(VHDL - from_usb_tx), which is pin 28
on the P3 header
4: USB RX must be connected to
(VHDL - to_usb_rx), which is pin 29
on the P3 header
It only required two extra VHDL
lines, and four Pin Planner entries to be
able to connect the other U3 UART on
the Expansion header to the CPLD and
another USB-Serial adapter, which is the
benefit of using a CPLD.
Installing Quartus2
I am not going to cover installation
and use of Quartus2, since there are a lot
of places on the Internet where you can
find installation guides it. One of them
is the Pyro course that I mentioned in
the beginning of the article.
I am using the 64-bit Linux edition
of the free Quartus2 Web Edition on
my Linux Mint 17 machine, but recommend
that most people use the Windows
version, since the Linux version usually
needs some additional libraries which
must be manually built, along with some
Quartus2 files that need to be modified.
The most recent version of Quartus2
that has MAX II support is Quartus2
v.13.0sp1. Do not install a newer version,
as it will not work properly. To
download it, visit http://bit.ly/1cdWtJg,
which requires registration. Select the
Combined files tab, and download the
Figure 8 - U3 UART header
ODROID MAGAZINE 43