HD-4702
Description
The HD-4702/883 Bit Rate Generator provides the necessary clock signals for digital data transmission systems, such as a UART. It generates 13 monly used bit rates using an on-chip crystal oscillator or an external input. For conventional operation generating 16 output clock pulses per bit period, the input clock frequency must be 2.4576MHz (i.e., 9600 Baud x 16 x 16, since there is an internal ÷ 16 prescaler). A lower input frequency will result in a proportionally lower output frequency. The HD-4702/883 can provide multi-channel operation with a minimum of external logic by having the clock frequency CO and the ÷ 8 prescaler outputs Q0 , Q1 , Q2 available externally. All signals have a 50% duty cycle except 1800 Baud, which has less than 0.39% distortion. The four rate select inputs (S0-S3) select which bit rate is at the output (Z). See Truth Table for Rate Select Inputs for select code and output bit rate. Two of the 16 select codes for the HD-4702/883 do not select an...
