fe EXAR XR-82C684 CMOS Quad Channel UART (QUART) PRELIMINARY GENERAL DESCRIPTION The EXAR Quad Universal ASynchronous Receiver and Transmitter (QUART) is a data communications device that provides four fully independent full duplex asynchronous communications channels in a single package. The QUART is designed for use in microprocessor based systems and may be used in a polled or interrupt driven environment. The XR-82C684 offers a single IC solution for various microprocessor families. The 88 and 68 modes can be selected by tying SEL pin to VDD or VSS. The QUART is fabricated using advanced two layer metal, with a high density EPI/CMOS process to provide high performance and low power consumption. FEATURES Four Full Duplex, Independent Channels, Asynchronous Receiver and Transmitter Quadruple Receive and Transmit Buffer Programmable Stop Bits in 1/16 Bit Increments Pin Selectable 88 and 68 mode Four Independent Internal Bit Rate Generator with more than 33 Bit Rates Independent Bit Rate Selection for each Transmitter and Receiver External Clock Capability Normal, Autoecho, Local Loop Back and Remote Loopback Modes Two Multifunction 16-Bit Counter/Timer Interrupt Output with Sixteen Maskable Interrupt Conditions Prioritized Interrupt Vector Output on Acknowledge Programmable Interrupt Daisy Chain 16 General Purpose Outputs 16 General Purpose Inputs with Eight Charge of State Detectors on Inputs Multidrop Mode Compatible with 8051 Nine-Bit Mode On Chip Oscillator for Crystal Stand-by Mode to Reduce Operating Power ABSOLUTE MAXIMUM RATINGS -65C to 150C -0.5V to +7 V Consult Factory for Package Information. Storage Temperature All Voltages with respect to ground 7-67 XR-82C684 XR-82C684 ELECTRICAL PERFORMANCE CHARACTERISTICS LIMITS GROUP A TEST SYMBOL| SEE NOTE 1 TEMPERATURE MIN MAX | UNIT | SUBGROUP Input Low Voltage ViL Ta = 425C -0.5 08 Vv 1 55C < TA< + 125C =| -0.5 0.8 Vv 2,3 Input High Voltage VIH Ta = +25C 20 Vv 1 -55C < TA < + 125C 2.2 Vv 23 Input High Voltage Ta = 425C 4.0 vcc Vv 1 (x1 / CLK) Vint -55C < TA< + 125C 4.0 vcc Vv 23 Output Low Voltage | Voi lo. = 2.4mA Ta = 425C 0.4 Vv 1 55C < TA< + 125C 0.4 Vv 2,3 Output High Voltage | Vou OH = -400pA Ta = +25C 2.4 Vv 1 (Except pen Drain -55C < TA< + 125C 2.4 Vv 2,3 Outputs) Input Leakage Ite VIN = 0 to Vec TA = +25C 15 15 pA 1 Current -55C < TA< + 125C -25 25 pA 2,3 Data Bus 3-State Ne Vo =0 to Vcc TA = +25C -10 10 HA 1 Leakage Current -55C < TA< + 125C -10 10 pA 2.3 Open Drain Output | loc Vo = 0 to Vec TA = 425C -10 10 pA 1 Leakage Current -55C < TA< + 125C -10 10 pA 2,3 Power Supply Active | icca TA = +25C 15 mA 1 Current 55C < TA < + 125C 15 mA 2,3 Power Supply IcCs Ta = +25C 10 mA 1 Standby Current -55C< Ta < + 125C 10 mA 2,3 Reset Pulse Width | tres TA = +25C 1.0 ps 9 -55C < TA< + 125C 1.0 ps 10,11 7-68 XR-82C684 XR-82C684 ELECTRICAL PERFORMANCE CHARACTERISTICS CONDITIONS LIMITS ROUP A TEST SYMBOL | SEENOTE1 TEMPERATURE MIN MAX | UNIT |SUBGROUP Port Input Set tps TA = +25C 0 ns 9 Up Time To RD/CS Low ~55C STA S$ + 125C 0 ns 10,11 Port Input Hold Time {PH TA = +25C 0 nS 9 From RD/CS High 55C < TAS + 125C 0 ns 10,11 Port Output Valid tPb TA = +25C 400 ns 9 From WR/CS High 55C < TAS + 125C 400 ns 10,11 Inter or OP3-OP7/ OP10-OP15 When Used as Interpt High From: Clear of Interrupt Status Bit in ISR or IPCR uR TA = +25C 300 nS 9 -55C Ss TAS + 125C 300 ns 10,11 Clear of Interrupt Mask tA Ta = +25C 300 ns In IMR -55C < TAS + 125C 300 nS 10,11 X1/CLK(external) High CLK TA = +25C 100 ns 9 or Low Time -55C < TAS + 125C 100 ns 10,11 X1/CLK Crystal or fcLk Ta = +25C 2.0 7.372| MHz 9 External Frequency -55C < TAS + 125C 2.0 7.372| MHz 10,11 Counter / Timer tcTc TA = +25C 100 ns 9 External Clock High -55C < TAS + 125C 100 ns 10,11 or Low Time (1P2/1P 10) Counter / Time fete Ta = +25C 0.0 7.372) MHz 9 External Clock -55C $< TAS + 125C 0.0 7.372] MHz 10,11 Frequency RXC and TXC tRTX TA = +25C 220 ns 9 (External) High or -55C < TAS + 125C 220 nS 10,11 Low Time 7-69 XR-82C684 XR-82C684 ELECTRICAL PERFORMANCE CHARACTERISTICS Rxe nd Txc fATX TA = +25C 0.0 16.0 | MHz 9 (External) 55C < TAS + 125C 0.0 16.0 | MHz 10, 11 Frequency 16X Rxe and Txc fATX TA = +25C 0.0 1.0 MHz 9 (External) -55C < TAS + 125C 0.0 4.0 MHz 10,11 Frequency 1X Txp Output tTxD TA = 425C 350 nS 9 Delay from Txc -55C < TAS + 125C 350 ns 10, 11 (External) Low TXD Output ttcs TA = +25C 0 150 ns -9 Delay from Txc -58C < TAS + 125C o 150 ns 10, 11 (Internal) Output Low RX[) Data Setup inxs TA = +25C 240 ns 9 Time to RXG -55C s TAS + 125C 240 ns 10, 11 External High Rxp Data Hold IRXH TA = +25C 200 ns 9 Time from Rxc -55C < TAS + 125C 200 ns 10,11 External High IE! Setup Time TEIs TA = +25C 50 nS 9 to RD Low 55C < TAS + 125C 50 ns 10,11 IEO Delay Time TeEoo TA = 425C 100 ns 9 from Internal Low -58C < TAS + 125C 100 ns 10,11 AO-A4 Setup tas TA = 425C 10 ns 9 Time to RD, -55C < TAS + 125C 10 ns 10,11 WR Low A0-A4 Hold AH TA = +25C 0 ns 9 Time from RD, -5SC < TAS + 125C 0 nS 10,11 WR Low CS Setup Time tcs TA = +25C 0 ns 9 to RD, WR Low -85C < TAS + 125C 0 ns 10,11 7-70 XR-82C684 XR-82C684 ELECTRICAL PERFORMANCE CHARACTERISTICS CS Hold Time CH TA = +25C 0 ns 9 from RD, WR -55CSTas+125C 0 nS 10,11 High RD, WR trw TA = +25C 225 ns 9 Pulse Width -55C<Tas+125C 225 ns 10,11 Data Valid from top TA = +28C 175 nS 9 RD Low -55CsTas+- 125C 175 ns 10, 11 Data Bus tOF Ta = +25C 10 100 ns 9 Floating from -55CSTAS+- 126C 10 100 ns 10, 11 RD High Data Setup Time tos Ta = +25C 100 ns 9 to WR High -55CSTAS+125C 100 ns 10,11 Data Hold Time tOH TA = +28C 5 ns 9 from WR High -55C<TAS+125C 5 ns 10, 11 High Time Between tRWD Ta = +25C 100 ns 9 Reads and/or Writes -55CSTas+125C 100 ns 10,11 IEO Delay Time tDIO TA = 425C 100 ns 9 from IEl -55CsTas+125C 100 ns 10,11 IACK Hold Time UAH Ta = +25C 0 ns 9 from RD High -55CSTAS+125C 0 ns 10, 11 7-71