MC68307V Datasheet, PDF (15/34 Pages) Motorola, Inc – Technical Summary Integrated Multiple-Bus Processor

UART MODULE
The UART module in the MC68307 is based on the MC68681 DUART, which is part of the M68000 family of
peripherals which directly interfaces to the MC68000 processor via an asynchronous bus structure. The UART
module consists of internal control logic, timing and baud-rate generator logic, interrupt control logic, and the
serial communications channel. Only one serial channel is implemented for the MC68307.
Clocking is provided by the MC68307 system clock, via a programmable prescaler. This allows various baud
rates to be chosen. Modem support is provided with request-to-send (RTS) and clear-to-send (CTS) signals
available. The serial port can sustain data rates of 5Mbits/s.
The features of the UART include:
• Full-duplex asynchronous/synchronous receiver/transmitter channels
• Maximum data transfer: 1X clock—5 Mbits/s, 16X clock—625 Kbits/s
• Quadruple-buffered receiver data registers
• Double-buffered transmitter data registers
• Programmable baud rate for serial channel
— User defined rate derived from a programmable timer
• Programmable data format
— Five to eight data bits plus parity
— Odd, even, no parity, or force parity
— One, one and one-half, or two stop bits programmable in 1/16 bit increments
• Programmable channel modes for diagnostics
— Normal (full duplex)/automatic echo/local loopback/remote loopback
• Automatic wake-up mode for multidrop applications
• Versatile interrupt system
— Single interrupt output with eight maskable interrupting conditions
— Interrupt vector output on interrupt acknowledge
• Parity, framing, and overrun error detection
• False-start bit detection
• Line-break detection and generation
• Detects break which originates in the middle of a character
• Interrupt or poll on start/stop break
MOTOROLA
MC68307 TECHNICAL INFORMATION
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