Quatech MPAP-100 - Manual (Page 54)

19 External Connections
The MPAP-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 --- MPAP-100 Clock Configuration