TINY-2/MICRO-2 Technical Ref., 2. Ed 1989
- 15 -
Pin 9 SIO CTS Input
This pin is an input to the SIO. It is high when the attached modem is not ready to accept
data, and low when the attached modem is ready to accept data. The packet controller will
not attempt to send data when this pin is high. This pin is normally jumpered to pin 10
when the on-board modem is used.
Pin 10 Modem CTS Output
This pin is used by the on-board modem to signal the SIO when it is ready to accept data.
This pin is normally jumpered to pin 9.
Pin 11 Transmitter Clock (16×) Input
This pin is tied to the NRZ-to-NRZI Converter, which expects a clock signal at 16 times the
desired radio port data rate, e.g. 4800 Hz for 300 bauds. This pin is normally jumpered to
pin 12 when the on-board modem is used.
Pin 12 Transmitter Clock (16×) Output
This pin is tied to the radio baud rate switch network. It provides a clock at 16 times the
desired radio port data rate. This pin is normally jumpered to pin 11 when the on-board
modem is used.
Pin 13 Receive Clock Input
This pin is tied to the SIO receive clock input pin. It expects a clock at the desired data rate
(1200 Hz for 1200 bauds), of the proper phase relationship to the received data, This pin is
normally jumpered to pin 14 when the on-board modem is used.
Pin 14 Receive Clock Output
This pin is the received data clock signal derived from the NRZI-to-NRZ converter. This pin
is normally jumpered to pin 13 when the on-board modem is used.
Pin 15 TINY-2/MICRO-2 Ground Reference
This pin ties to the TINY-2/MICRO-2 digital ground at the SIO.
Pin 16 Additional Ground Reference
Pin 17 Receive Data Input
This pin is the received data input to the NRZI-to-NRZ Converter. This pin is normally jum-
pered to pin 18 when the on-board modem is used.
Pin 18 Receive Data Output
This pin provides receive data from the on-board modem. This pin is normally jumpered to
pin 17 when the on-board modem is used.
Pin 19 Transmit Data Output
This line is the SIO data output. This pin is normally jumpered to pin 20 when the on-board
modem is used.
Pin 20 Transmit Data Input
This input line accepts data to be be transmitted by the modem. This pin is normally jum-
pered to pin 19 when the on-board modem is used.