The maximum clock frequency for the CD74HC163M is 25 MHz, but it can vary depending on the operating voltage and temperature. It's recommended to check the timing diagrams and electrical characteristics in the datasheet to ensure the desired clock frequency meets the setup and hold time requirements.
The asynchronous reset (RST) input should be asserted low to reset the counter. When RST is low, the counter is reset to zero, and the output (Q0-Q3) is set to zero. The RST input should be synchronized with the clock (CLK) input to avoid metastability issues.
The Enable (EN) input allows the counter to be enabled or disabled. When EN is high, the counter is enabled and counts up or down based on the clock (CLK) and load (LD) inputs. When EN is low, the counter is disabled, and the output (Q0-Q3) remains unchanged.
To load a preset value into the counter, assert the Load (LD) input low, and apply the desired value to the parallel data inputs (D0-D3). The counter will load the preset value when LD returns high.
The output (Q0-Q3) is a binary-coded decimal (BCD) format, where each output represents a 4-bit binary code (0000 to 1001) that corresponds to a decimal value from 0 to 9.
CD74HC163M datasheet
by Texas Instruments
