BR1941 Datasheet | Western Digital

WESTERN DIGITAL c o Rp o RA T/ o N BR1941 Dual Baud Rate Clock Features .. 16 SELECTABLE BAUD RATE CLOCK FREQUENCIES - DUAL SELECTABLE 16 X CLOCK OUTPUTS FOR FULL DUPLEX OPERATIONS - OPERATES WITH CRYSTAL OSCILLATOR OR EXTERNALLY GENERATED FREQUENCY INPUT .. ROM MASKABLE FOR NON-STANDARD FREQUENCY SELECTIONS .. INTERFACES EASILY WITH MICROPUTERS .. OUTPUTS A 50% DUTY CYCLE CLOCK WITH 0.01% ACCURACY .. 18 PIN CERAMIC DIP PACKAGE o 3 DIFFERENT FREQUENCY/DIVISOR PAIRS AVAILABLE GENERAL DESCRIPTION The BR1941 is a bination Baud Rate Clock Generator and Programmable Divider. It is manufactured in N-channel MOS using silicon gate technology. This device is capable of generating 16 externally selected clock rates whose frequency is determined by either a single crystal or an externally generated input clock. The BR1941 is a programmable counter capable of generating a division from 2 to (215 -1). :.:- II: ~ :li ~ The BR1941 is available programmed with the most used frequencies in data munication. Each frequency is selectable by strobing or hard wiring each of the two sets of four Rate Select inputs. Other frequencies/division rates can be generated by reprogramming the internal ROM coding through a MOS mask change. Additionally, further clock division may be acplished through cascading of devices. The frequency output is fed into the XTAL/EXT input on a subsequent device. The BR1941 can be driven by an external crystal or by TIL logic. XTAl/EXT 1 +5V f R RA RS RC RD STR +12V XTAl IEXT 2 f T TA T8 TC TO STT GND NC- -INTERNALLY BONDED. DO NOT CONNECT ANYTHING TO THIS PIN. PIN CONNECTIONS TA TB TC TC STT RA RB RC RD FT FR BR1941 BLOCK DIAGRAM PIN...