background image

 

1300 Henley Court 

Pullman, WA 99163 

509.334.6306 

www.digilentinc.com 

PmodPS/2

™ Reference Manual

 

 

Revised May 26, 2016 
This manual applies to the PmodPS/2 rev. C 

 

DOC#: 502-094 

Copyright Digilent, Inc. All rights reserved. 

Other product and company names mentioned may be trademarks of their respective owners.

 

Page 1 of 4 

 

 

Overview 

The Digilent

 

PmodPS/2

 

is a module that allows users to attach a PS/2 compatible keyboard or mouse to their 

system board. 

 

Functional Description 

The PmodPS/2 module is a standard PS/2 connector that by nature of the PS/2 supports N-KEY rollover. This is a 
feature that guarantees that every movement and key press will be received and addressed. Naturally, whether or 
not the key press will actually perform a function is dependent on the software, but the system board will still 
receive all of the inputs. 

 

Interfacing with the Pmod 

The PmodPS/2 communicates with the host board via the

 

GPIO protocol. Both the keyboard and mouse will use a 

data and a clock line to communicate their information to the system board. Specific details on how this is done 
are available in their respective sections below. 

 

 

 

 

The PmodPS/2. 

 
 

 

Standard PS/2 port 

 

Jumper to allow for an external power source 

 

Small PCB size for flexible designs 1.0“ × 0.8” (2.5 cm × 
2.0 cm) 

 

6-pin Pmod connector with GPIO interface 

 

Follows 

Digilent Pmod Interface Specification

 Type 1 

 

Example code available in 

resource center

 

 

Features include: 

Summary of Contents for PmodPS/2

Page 1: ...y movement and key press will be received and addressed Naturally whether or not the key press will actually perform a function is dependent on the software but the system board will still receive all of the inputs 2 Interfacing with the Pmod The PmodPS 2 communicates with the host board via the GPIO protocol Both the keyboard and mouse will use a data and a clock line to communicate their informa...

Page 2: ... 2 Reserved 3 GND 4 Vdd 5 Clock 6 Reserved 1 5 3 2 4 6 Pin 2 TCK TSU Edge 0 Edge 10 CLK DATA THLD TCK 1 stop bit 0 start bit Symbol Parameter Min Max Tck Clock time 30us 50us Tsu Data to clock setup time 5us 25us Thld Clock to data hold time 5us 25us Table 2 Bus timings 3 1 Keyboard The keyboard uses open collector drivers so that either the keyboard or an attached host device can drive the two wi...

Page 3: ... N 31 M 3A 41 49 4A Shift 59 Alt 11 Space 29 Alt E0 11 Ctrl E0 14 F1 05 F2 06 F3 04 F4 0C F5 03 F6 0B F7 83 F8 0A F9 01 F10 09 F11 78 F12 07 E0 75 E0 74 E0 6B E0 72 The keyboard sends data to the host only when both the data and clock lines are high or idle Since the host is the bus master the keyboard checks to see whether the host is sending data before driving the bus To facilitate this the clo...

Page 4: ...f mouse movement the larger the number the faster the mouse is moving the XV and YV bits in the status byte are movement overflow indicators a 1 means overflow has occurred If the mouse moves continuously the 33 bit transmissions are repeated every 50ms or so The L and R fields in the status byte indicate Left and Right button presses a 1 indicates the button is being pressed L R 0 1 XS YS XY YY P...

Page 5: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Digilent 410 094P 410 094 ...

Reviews: