Overview
The CD1865 is a cost-effective controller capable of controlling eight full-duplex channels transferring data at rates up to 115.2 kbps. The advantage of the CD1865 lies in its ability to efficiently move data from the serial channels to the host. This results in an order-of-magnitude improvement in system-level throughput and a reduction in overhead on the host CPU.

Product Features
■ Eight full-duplex asynchronous channels
   supporting data rates up to 115.2 kbps
   Note: To support this data rate, the
   specified system clock frequency is
   required.
■ Register-based interrupt acknowledges
   eliminate need for separate interrupt
   acknowledge signals
■ Automatic prioritizing scheme allows
   device to respond to an interrupt
   acknowledge with the highest internal
   interrupt pending (host-programmable)
■ Sophisticated interrupt schemes
   —Vectored interrupts
   —Fair Share interrupts
   —Good Data interrupts for improved
      throughput
   —Simultaneous interrupt requests for three
      classes of interrupts: Rx, Tx, and
      modem state changes
■ Independent baud-rate generators for each
   channel/direction
■ Software compatibility with the CD180 and
   CD1864 devices
■ Generation and detection of special
   characters
■ Automatic flow control
   —In-band (Xon, Xoff generation, and
      detection)
   —Out-of-band (DTR/DSR or RTS/CTS)
■ On-chip FIFO — 8 bytes each for Rx, Tx,
   and Status
■ Line break detection and generation
■ Multiple-chip daisy-chain cascading
   feature
■ Odd, even, forced, or no parity
■ modem/general-purpose I/O signals per
   channel
■ System clock up to 66 MHz (x2), 33MHz
   (x1)
■ CMOS technology in 100-pin MQFP