Zilog EZ80F91 - Manual (Page 38)

eZ80F91 Development Kit
User Manual
UM014220-0508 eZ80 Development Kit
33
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.
Push Buttons
The eZ80Acclaim!
®
Development Kit provides user controls in the form
of push buttons. These push buttons serve as input devices to the eZ80F91
device. You can use them as necessary for application development. All
push buttons are connected to the GPIO Port B pins.
PB0
The PB0 push button switch, SW1, is connected to bit 0 of GPIO Port B.
This switch can be used as the port input if required.
PB1
The PB1 push button switch, SW2, is connected to bit 1 of GPIO Port B.
This switch can be used as the port input if required.
PB2
The PB2 push button switch, SW3, is connected to bit 2 of GPIO Port B.
This switch can be used as the port input if required.