4串口扩展芯片

The XR16C8641 (864) is an enhanced quad Universal Asynchronous Receiver and Transmitter (UART) each with 128 bytes of transmit and receive FIFOs, transmit and receive FIFO counters and trigger levels, automatic hardware and software flow control, automatic RS-485 half-duplex direction control and data rates of up to 2 Mbps. Each UART has a set of registers that provide the user with operating status and control, receiver error indications, and modem serial interface controls. System interrupts may be tailored to meet design req uirements. An internal loopback capability allows onboard diagnostics. The 864 is available in the 100- pin QFP package. The XR16C864 offers faster channel status access by providing separate outputs for TXRDY and RXRDY, offer separate Infrared TX outputs and a separate clock input for channel C (CHCCLK).