APPENDIX A ■ APPENDIX A
Practical Example
On a 74LS04 (bipolar-based) chip, the power supply pins are labeled VCC and GND. The positive bus
connects to the VCC pin and the ground bus (formerly “negative”) connects to GND.
The power supply pins of a Freescale 68HC908KX8 (field-effect based) microcontroller are labeled VDD
and VSS. The positive bus connects to the VDD pin and the ground bus (formerly “negative”) connects to VSS.