Datasheet

CoolRunner-II™ Starter Board Reference Manual

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Page 4 of 4

5 Expansion Connectors

The CoolRunner-II board provides four 12-pin peripheral module ports. Each port provides two V

and GND

connections and eight unique CPLD signals. Each port can accommodate a single 12-pin Pmod or two 6-pin Pmods.

Digilent makes several 6-pin Pmods that can attach to these ports, including speaker boards, H-bridge boards,

sensor boards, etc. See www.digilentinc.com for more information.

The CoolRunner-II board also provides a 40-pin expansion connector that includes three power-supply signals and

37 individual I/O signals.

6 Demonstration Design

The design pre-programmed onto the CPLD contains several functions that can be seen when the appropriate

peripheral modules are inserted into the relevant ports.

In this sample design, the switch Pmod goes in port J8, the PS/2 Pmod goes in port J7, and the seven-segment

display Pmod goes in ports J5 and J6. Of course, the design can be changed to use different ports.

The CPLD implements both a counter as well as a PS/2 keyboard decoder. The display switches between the two

based on the value of SW4. SW1, 2, and 3 are not used in the design. BTN0 is the system reset for the design.

When SW4 has the PS/2 decoder selected, the output on the display is the scan code for that letter. Here are some

scan codes, the rest can be found on the Internet.

Keyboard Key

Scan Code

Keyboard Key

Scan Code

7 Design Recommendations

 The regulator provides Vccio of 3.3V, so set the Default I/O Standard appropriately.

 Unused I/O should be set to Ground to minimize power.

 Input Termination should be set to Keeper to minimize power consumption on any potentially floating

input pins.