Digilent Ceres - Manual (Page 4)

Ceres Reference Manual Digilent, Inc.
www.digilentinc.com ® Digilent, Inc. Page 4
Digit Cathode Signals
Shown a b c d e f g
0 0 0 0 0 0 0 1
1 1 0 0 1 1 1 1
2 0 0 1 0 0 1 0
3 0 0 0 0 1 1 0
4 1 0 0 1 1 0 0
5 0 1 0 0 1 0 0
6 0 1 0 0 0 0 0
7 0 0 0 1 1 1 1
8 0 0 0 0 0 0 0
9 0 0 0 1 1 0 0
Figure 9. Sseg cathode signals for digits
Expansion connector
An expansion connector labeled J1 is included
on the edge of the Ceres board to allow
designs to be expanded beyond the board. No
connector is loaded during manufacturing to
allow greater flexibility (so that wire-wrap pins
can be loaded, or a male or female connector).
All available CPLD signals are routed to the
connector, including signals that drive on-
board devices. Where feasible, on-board
devices are decoupled from the CPLD with
series resistors so that all pins may be used as
inputs or outputs by the expansion connector.
VCC and GND are also routed to the
connector so that attached devices can draw
power from the Ceres board. Table 1 shows
the signals routed to the expansion connector.
40 Pin DIP Socket
The Ceres Board is designed to accept any
one of several C-Mod boards. C-Mods can
easily be inserted into or removed from the 40
pin DIP socket. To add or change a C-Mod
board, power off the Ceres (disconnect the
power supply), remove an existing C-Mod
board if needed, and press the new C-Mod into
the DIP socket, ensuring that Pin 1 on the C-
Mod is aligned with Pin 1 on the socket. Table
2 shows the signals routed to the 40-pin DIP
socket.
Table 1. Ceres expansion connector pinout
Pin Signal Pin Signal Pin Signal Pin Signal
1 GND 11 SW4 21 NC 31 LED4
2 VU 12 BTN2 22 AN1 32 CE
3 VCC 13 SW3 23 NC 33 LED3
4 NC 14 BTN1 24 AN2 34 CD
5 SW7 15 SW2 25 LED7 35 LED2
6 NC 16 BTN0 26 AN3 36 CC
7 SW6 17 SW1 27 LED6 37 LED1
8 NC 18 DP 28 CG 38 CB
9 SW5 19 SW0 29 LED5 39 LED0
10 BTN3 20 AN0 30 CF 40 CA
Table 2. Ceres board 40-DIP pinout
Pin Signal Pin Signal Pin Signal Pin Signal
1 CA 11 CG 21 GND 31 LED6
2 CB 12 AN3 22 SW6 32 LED5
3 CC 13 AN2 23 SW5 33 BTN0
4 CD 14 AN1 24 SW4 34 BTN1
5 NC 15 AN0 25 SW3 35 MCLK
6 NC 16 SW7 26 SW2 36 LED4
7 NC 17 DP 27 SW1 37 LED3
8 NC 18 BTN3 28 BTN2 38 LED2
9 CE 19 NC 29 SW0 39 LED1
10 CF 20 VCC 30 LED7 40 LED0