User`s manual

18 External Connections

The MPAC-100 is configured as a Data Terminal Equipment (DTE) device,

meeting the RS-232-D standard using a DB-25 male connector. There is no DCE version

available.

The control signals the DTE can generate are Request To Send (RTS) and Data

Terminal Ready (DTR). It can receive the signals Carrier Detect (DCD), Clear to Send

(CTS), and Data Set Ready (DSR). All the control signals are controlled through channel

A of the SCC, with the exception of the DSR signal, which is received on the DCDB pin

on channel B. (The SCC has no actual DSR inputs.)

The DTE can transmit its transmit clock (TCLK) from the TRxCA pin of the SCC,

or receive TCLK on the same pin. The DTE can also receive its receive clock (RCLK) on

the RTxC pins on channels A & B of the SCC, or can generate RCLK using the TRxCB

pin. TCLK and RCLK can also be internally sourced from the channel A baud rate

generator.

Figure 1 shows the DTE clock configuration. On the left are the SCC clock pins

and the clock enable bits from the Communications Register. On the right are the

signals at the DB-25 connector. Figure 2 illustrates the connector pinout.

TRxCA

RTxCA

RTxCB

RXCLK (DCE)

RXCLK (DTE)

TRxCB

RCKEN

TXCLK (DTE)

TXCLK (DCE)

TCKEN

(RCLK)

(TCLK)

Figure 1 --- MPAC-100 Clock Configuration

Quatech MPAC-100 User's Manual