PC87393VJG National Semiconductor, PC87393VJG Datasheet - Page 84

• Manufacturer Part Number: PC87393VJG
• Description: IC, SUPER I/O DEVICE, TQFP-100
• Manufacturer: National Semiconductor

Specifications of PC87393VJG

• Data Rate: 2Mbps
• Supply Voltage Range: 3V to 3.6V
• Logic Case Style: TQFP
• No. Of Pins: 100
• Operating Temperature Range: 0°C to +70°C
• Termination Type: SMD
• Transceiver Type: Interface
• Rohs Compliant: No

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5.0 Game Port (GMP)
Note: This section applies to the PC87393 and PC87393F only.
5.1 OVERVIEW
This chapter describes a generic Game Port. For the implementation used in this device, see the Device Architecture and
Configuration chapter.
The Game Port monitors the interface of up to two game devices, and provides data that can be used to determine the exact
momentary status of these game devices.
A game device is an instrument used for giving commands to a PC, usually to control a game executed on that PC. A Joystick
is a commonly used game device. These commands are given by the game device in a passive manner, by indicating sev-
eral status parameters that can be captured by the system via the Game Port.
The status of a game device includes the following parameters:
Figure 13 shows the basic system configuration of the Game Port.
5.2 FUNCTIONAL DESCRIPTION
5.2.1
A typical game device has the following interface pins:
The X and Y axis indicators are fed into the Game Port via pins JOYnX and JOYnY, respectively, where ‘n’ indicates the
game device number. The status indicators of buttons 0 and 1 are fed into the Game Port via JOYnBTN0,1, respectively.
The X and Y axis position indication mechanism of each game device includes external components, as seen in Figure 14.
Such a mechanism is implemented per game device axis line.
Button status (pressed/released) of up to two buttons per game device
Horizontal (X-axis) position indicated by the game device
Vertical (Y-axis) position indicated by the game device.
an X-axis position indicator
a Y-axis position indicator
one or two button status indicator(s).
Game Device Axis Position Indication
Game
Port
Game
Port
X/Y-Axis
Circuit
Discharge
Control
X/Y-Axis
Indicators
Input
Path
Figure 14. Game Device Axis Position Indication Mechanism
Figure 13. Game Port System Configuration
X-Axis
Y-Axis
Button 1
Button 0
JOYnX
JOYnY
Game Device
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Interface
Pins
Circuitry
Device
Game
Waveform Shaping Circuit
C
X
X-Axis
Y-Axis
Button 1
Button 0
R
CX
Device A
Game Device
X/Y-Axis Varying
Resistor
Game
Device
Game
R
VX