| X2 RxDA RxDB TxDA TxDB OPO OP1 OP2 OP3 OP4 OP5 OP6 OP7 IPO IP1 IP2 IP3 IP4 IP5 IP6 Vcc GND n.c. | 37 35 11 33 13 32 14 31 15 30 16 29 17 8 5 40 3 43 42 41 44 22 1, 12, 34, 23 | 33 31 10 30 11 29 12 28 13 27 14 26 15 7 4 36 2 39 38 37 40 20 | 24 22 7 21 8 20 9 27 28 14 | I I I 0 0 0 0 0 0 0 0 0 0 I I I I I I I I I | Crystal 2: Crystal connection. See Figure 7. If a crystal is not used it is best to keep this pin not connected although it must not be grounded. Channel A Receiver Serial Data Input: The least significant bit is received first. "Mark" is HIGH, "space" is LOW. Channel B Receive Serial Data Input: The least significant bit is received first. "Mark" is HIGH, "space" is LOW. Channel A Transmitter Serial Data Output: The least significant bit is transmitted first. This output is held in the "mark" condition when the transmitter is disabled, idle or when operating in local loopback mode. "Mark" is HIGH, "space" is LOW. Channel B Transmitter Serial Data Output: The least significant bit is transmitted first. This output is held in the "mark" condition when the transmitter is disabled, idle or when operating in local loopback mode. "Mark" is HIGH, "space" is LOW. Output 0: General purpose output or Channel A request to send (RTSAN, active-LOW). Can be deactivated automatically on receive or transmit. Output l: General purpose output or Channel B request to send (RTSBN, active-LOW). Can be deactivated automatically on receive or transmit. Output 2: General purpose output or Channel A transmitter lx or 16x clock output, or Channel A receiver l x clock output. Output 3: General purpose output or open-drain, active-LOW counter/timer interrupt output or Channel B transmitter lx clock output, or Channel B receiver l x clock output. Output 4: General purpose output or Channel A open-drain, active-LOW, RxRDYA/FFULLA interrupt output. Output 5: General purpose output or Channel B open-drain, active-LOW, RxRDYB/FFULLB interrupt output. Output 6: General purpose output or Channel A open-drain, active-LOW, TxRDYA interrupt output. Output 7: General purpose output or Channel B open-drain, active-LOW, TxRDYB interrupt output. Input O: General purpose input or Channel A clear to send active-LOW input (CTSAN). Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input l: General purpose input or Channel B clear to send active-LOW input (CTSBN). Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input 2: General purpose input or counter/timer external clock input. Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input 3: General purpose input or Channel A transmitter external clock input (TxCA). When the external clock is used by the transmitter, the transmitted data is clocked on the falling edge of the clock. Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input 4: General purpose input or Channel A receiver external clock input (RxCA). When the external clock is used by the receiver, the received data is sampled on the rising edge of the clock. Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input 5: General purpose input or Channel B transmitter external clock input (TxCB). When the external clock is used by the transmitter, the transmitted data is clocked on the falling edge of the clock. Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Input 6: General purpose input or Channel B receiver external clock input (RxCB). When the external clock is used by the receiver, the received data is sampled on the rising edge of the clock. Pin has an internal Vcc pull-up device supplying l t0 4.A of current. Power Supply: +5V supply input. Ground Not connected. |
