description
●The TL16C550A is a functional upgrade of the TL16C450 asynchronous communications element (ACE). Functionally identical to the TL16C450 on power up (character mode†), the TL16C550A can be placed in an alternate mode (FIFO) to relieve the CPU of excessive software overhead.
●In this mode, internal FIFOs are activated allowing 16 bytes (plus 3 bits of error data per byte in the receiver FIFO) to be stored in both receive and transmit modes. To minimize system overhead and maximize system efficiency, all logic is on the chip. Two of the TL16C450 terminal functions (terminals 24 and 29 on the N package and terminals 27 and 32 on the FN package) have been changed to allow signalling of direct memory address (DMA) transfers.
●Capable of Running With All Existing TL16C450 Software
●After Reset, All Registers Are Identical to the TL16C450 Register Set
●In the FIFO Mode, Transmitter and Receiver Are Each Buffered With 16-Byte FIFOs to Reduce the Number of Interrupts to the CPU
●In the TL16C450 Mode, Holding and Shift Registers Eliminate the Need for Precise Synchronization Between the CPU and Serial Data
●Programmable Baud Rate Generator Allows Division of Any Input Reference Clock by 1 to (216–1) and Generates an Internal 16×Clock
●Standard Asynchronous Communication Bits (Start, Stop, and Parity) Added to or Deleted From the Serial Data Stream
●Independent Receiver Clock Input
●Transmit, Receive, Line Status, and Data Set Interrupts Independently Controlled
●Fully Programmable Serial Interface Characteristics:
●– 5-, 6-, 7-, or 8-Bit Characters
●– Even-, Odd-, or No-Parity Bit Generation and Detection
●– 1-, 1 1/2-, or 2-Stop Bit Generation
●– Baud Generation (dc to 256 Kbit/s)
●False-Start Bit Detection
●Complete Status Reporting Capabilities
●3-State TTL Drive Capabilities for
●Bidirectional Data Bus and Control Bus
●Line Break Generation and Detection
●Internal Diagnostic Capabilities:
●– Loopback Controls for Communications Link Fault Isolation
●– Break, Parity, Overrun, Framing Error Simulation
●Fully Prioritized Interrupt System Controls
●Modem Control Functions (CTS, RTS, DSR, DTR, RI, and DCD)
●Faster Plug-In Replacement for National Semiconductor NS16550A
