Leds; Push Buttons - ZiLOG eZ80L92 User Manual

eZ80L92 Development Kit
User Manual
34

LEDs

Push Buttons

Operational Description
As stated earlier, LEDs D1, D2, D3, and D4 function as status indicators
for an optional modem. This section describes each LED and the LED
matrix device.
Data Carrier Detect
The Data Carrier Detect (DCD) signal at D1 indicates that a good carrier
signal is being received from the remote modem.
RX
The RX signal at D2 indicates that data is received from the modem.
Data Terminal Ready
The Data Terminal Ready (DTR) signal at D3 informs the modem that the
PC is ready.
TX
The TX signal at D4 indicates that data is transmitted to the modem.
®
The eZ80 Development Platform provides user controls in the form of
push buttons. These push buttons serve as input devices to the eZ80L92
microprocessor. The programmer can use them as necessary for applica-
tion development. All push buttons are connected to the general-purpose
port pins.
PB0
The PB0 push button switch, SW1, is connected to bit 0 of the general-
purpose port. This switch can be used as the port input if required by the
user.
PRELIMINARY UM012906-0103