5 s emiconductor , i nc. fea tures ? 5v operation ? full duplex asynchronous receiver and transmitter ? easily int erfac es to most popular mic ropr o c essors ? adds or deletes standard asynchronous com- munication bits (start, stop, and parity ) to or from a serial data stream ? independently controlled transmitter , receiver , line status, and data set interrupts ? programmable baud rate generator allows division of any input clock by 1 to (2 16 -1) and generates the internal 16 x clock ? independent receiver clock input ? modem control functions (cts, r ts, dsr, dtr, ri, and dcd) ? fully programmable serial interface characteris tics: - 5, 6, 7, or 8 bit characters - even, odd, or no-parity bit generation and detection - 1, 1.5, or 2 stop bit generation - baud generation (dc to 56k baud) ? false start bit detection pin configura tion ? complete status reporting capabilities ? t ri-state ? ttl drive capabilities for bi-direc tional data bus and control bus ? line break generation and detection ? internal diagnostic capabilities: - loopback controls for communications link fault isolation - break, parity overrun, and framing error simulation ? fully prioritized interrupt systems controls description the epic EI16C450 universal asynchronous receiver t ransmitter (uar t) is a cmos-vlsi communication device in a single package. the uar t performs serial to paralle l conversion on d ata characters received from a peripheral device or a modem, and parallel-to-serial conversions on data characters received from the cpu. the cpu can read the complete status of the uar t at any time during the functional operation. status information reported includes the type and con- dition of the transfer operation being performed by the uar t , as well as any error conditions (parity , overrun, framing, or break detect). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 e i 1 6 c 4 5 0 d0 d1 d2 d3 d4 d5 d6 d7 rclk sin sout cs0 cs1 cs2 ? baudout ? xt al1 xt al2 dostr ? dostr vss vcc ri ? dcd ? dsr ? cts ? mr out1 ? dtr ? r ts ? out2 ? intrpt nc a0 a1 a2 ads ? csout ddis distr distr ? 39 38 37 36 35 34 33 32 31 30 29 7 8 9 10 11 12 13 14 15 16 17 d5 d6 d7 rclk sin nc sout cs0 cs1 cs2 ? baudout ? mr out1 ? dtr ? r ts ? out2 ? nc intrpt nc a0 a1 a2 xt al1 xt al2 dostr ? dostr vss nc distr ? distr ddis csout ads ? d4 d3 d2 d1 d0 nc vcc ri ? dcd ? cdsr ? cts ? 18 19 20 21 22 23 24 25 26 27 28 6 5 4 3 2 1 44 43 42 41 40 EI16C450 EI16C450 ua r t 40-pin dip 44-pin plcc 36 n.c. 35 reset 34 op1 ? 33 dtr ? 32 r ts ? 31 op2 ? 30 int 29 n.c. 28 a0 27 a1 26 a2 25 n.c. n.c. 1 d5 2 d6 3 d7 4 rclk 5 n.c. 6 rx 7 tx 8 cs0 9 cs1 10 cs2 ? 1 1 baudout ? 12 48 n.c. 47 d4 46 d3 45 d2 44 d1 43 d0 42 vcc 41 ri 40 dcd ? 39 dsr ? 38 cts ? 37 n.c. n.c. 13 xt al1 14 xt al2 15 iow ? 16 iow ? 17 gnd 18 ior ? 19 ior 20 n.c. 21 ddis ? 22 csout 23 as ? 24 48-pin tqfp EI16C450
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