COM5026T Datasheet | SMSC

STANDARD MICROSYSTEMS CORPORATION 5026 5026T Baud Rate Generator Programmable Divider Features o On chip crystal oscillator or external frequency input o Choice of 16 output frequencies 016 asynchronous/synchronous baud rates o Direct UART/USRT/ ASTRO/USYNRT patibility o TTL, MOS patibility PIN CONFIGURATION XTAL/EXT1 11 XTAL/EXT2 21 +5v 31 NC 41 GND 51 NC 61 + 12v 71 "-/ 14 t OUT 13 A 12 B 11 C 10 0 9 ST 8 NC BLOCK DIAGRAM A REPROGRAMMABLE B FREQUENCY SELECT C D ROM XTALl EXTl XTALl EXT2 XTAL ~ ~----------~ CLOCK BUFFER DIVIDER f OUT ~ AA +5V ,GND +12V GENERAL DESCRIPTION The Standard Microsystems 5026 Baud Rate Generator/Programmable Divider is an N-channel COPLAMOS~ Ma S/LSI device which, from a single crystal (on-chip oscillator) or input frequency is capable of generating 16 externally selectable frequencies. The 5026 is specifically dedicated to generating the full spectrum of 16 asynchronous/synchronous data munication frequencies as shown in Table 1. One of the sixteen output frequencies is externally selected by four address inputs, as shown in Table 1. Internal re-programmable ROM allows the generation of other frequencies from other crystal frequencies or input frequencies. The four address inputs may be strobe (150ns) or DC loaded. The 5026 is basically a programmable 15-stage feedback shift register capable of dividing any modulo up to (21L 1). By using the frequency output, it is possible to generate additional divisions of the master clock frequency by cascading 5026's. The frequency output is fed into the XTAL/EXT input on a subsequent device. In this way one crystal or input frequency may be used to generate numerous output frequencies. The 5026 can be driven by either an external crystal or TTL logic level inputs; 5026T is driven by TTL logic level inputs only. Description of Pin...