INTEGRATED CIRCUITS SC28C94 Quad universal asynchronous receiver/transmitter (QUART) Product data sheet 2006 Aug 09 Supersedes data of 1998 Aug 19 Philips Semiconductors Product data sheet Quad universal asynchronous receiver/transmitter (QUART) SC28C94 DESCRIPTION Baud rate for the receiver and transmitter selectable from: The 28C94 quad universal asynchronous receiver/transmitter 23 fixed rates: 50 to 230.4K baud Non-standard rates to (QUART) combines four enhanced Philips Semiconductors 1.0 M baud industry-standard UARTs with an innovative interrupt scheme that User-defined rates from the programmable counter/timer can vastly minimize host processor overhead. It is implemented associated with each of two blocks using Philips Semiconductors high-speed CMOS process that External 1x or 16x clock combines small die size and cost with low power consumption. Parity, framing, and overrun error detection The operating speed of each receiver and transmitter can be selected independently at one of eighteen fixed baud rates, a 16X False start bit detection clock derived from a programmable counter/timer, or an external 1X Line break detection and generation or 16X clock. The baud rate generator and counter/timer can operate directly from a crystal or from external clock inputs. The Programmable channel mode ability to independently program the operating speed of the receiver Normal (full-duplex), automatic echo, local loop back, remote and transmitter make the QUART particularly attractive for loopback dual-speed channel applications such as clustered terminal systems. Programmable interrupt priorities Each receiver is buffered with eight character FIFOs (first-in-first-out Identification of highest priority interrupt memories) and one shift register to minimize the potential for Global interrupt register set provides data from interrupting receiver overrun and to reduce interrupt overhead in interrupt driven channel systems. In addition, a handshaking capability is provided to disable a remote UART transmitter when the receiver buffer is full. (RTS Vectored interrupts with programmable vector format control) IACKN and programmable DTACKN signals The 28C94 provides a power-down mode in which the oscillator is Built-in baud rate generator with choice of 18 rates stopped and the register contents are stored. This results in reduced power consumption on the order of several magnitudes. The Four I/O pins per UART for modem controls, clocks, etc. QUART is fully TTL compatible and operates from a single +5V power supply. Power down mode High-speed CMOS technology FEATURES 52-pin PLCC package New low overhead interrupt control Commercial and industrial temperature ranges available All commercial parts meet industrial timing and temperature On-chip crystal oscillator parameters Four Philips Semiconductors industry-standard UARTs TTL compatible Eight byte receive FIFO and eight byte transmit FIFO for each Single +5V power supply with low power mode UART Two multifunction programmable 16-bit counter/timers Programmable data format: 1MHz 16x mode operation 5 to 8 data bits plus parity 10ns data bus release time Odd, even, no parity or force parity 1, 1.5 or 2 stop bits programmable in 1/16-bit increments Watch Dog timer for each receiver ORDERING INFORMATION INDUSTRIAL PACKAGES DWG V = +5 V 10 %, CC T = 40 C to +85 C A 52-Pin Plastic Leaded Chip Carrier (PLCC) Package SC28C94A1A SOT238-2 2006 Aug 09 2