Xor-gate-up-down-counter
An ordinary binary counter, such as the 7493, can be transformed into an up/down counter with mode control by adding XOR gates (7486) to the counter's outputs. The circuit counts up when the DN/UP line is low and counts down when the DN/UP line is high. To utilize the 7493 counter for its maximum count range of 0 to 15, connect the QA output to the BIN input and apply clock pulses to the A IN input. The reset input, when high, inhibits the count inputs and simultaneously sets the outputs A0 through D0 to low in the up-count mode or to 15 in the down-count mode. For normal counting, the reset input must be low. This counter can be easily cascaded by feeding the Qv line to the clock input of a subsequent counter.
The 7493 binary counter is a versatile device that can be configured for various counting applications. By integrating XOR gates (7486) into the design, the functionality of the counter can be expanded to include both counting up and counting down. The DN/UP control line serves as the mode selector, determining the counting direction based on its voltage level. When the DN/UP line is low, the counter increments its value with each clock pulse applied to the A IN input. Conversely, when the DN/UP line is high, the counter decrements its value.
To achieve the maximum counting range of 0 to 15, it is essential to connect the QA output to the BIN input, ensuring that the counter operates within its defined limits. The reset input plays a crucial role in managing the counter's state. When activated (high), it disables the counting process and resets the outputs to a defined state. In up-count mode, the outputs reset to 0, while in down-count mode, they reset to 15. For the counter to function normally, the reset input must remain low, allowing for continuous counting.
Cascading multiple 7493 counters is straightforward and enables the creation of larger counting systems. By connecting the Qv output of one counter to the clock input of the next, a seamless transition of counting can occur, expanding the overall counting range and functionality. This cascading technique is particularly useful in applications requiring higher binary counts, such as digital clocks, frequency dividers, and other sequential logic circuits.One can transform an ordinary binary counter, such as a 7493, into an up/down counter with mode control by adding XOR gates 7486 to the counter"s outputs. The circuit counts up when the DN/UP line is low and down when the DN/UP line is high. To use the 7493 counter to count out its maximum count length of 0 -15, connect the QA output to the BIN input and apply clock pulses to the A IN input.
The reset input, when high, inhibits the count inputs and simultaneously returns the outputs Ao through Do to low in the up-count mode or 15 in the down-count mode. For normal counting, the reset input must be low. One can easily cascade this counter by feeding the Qv line to the clock input of a succeeding counter.
🔗 External reference
The 7493 binary counter is a versatile device that can be configured for various counting applications. By integrating XOR gates (7486) into the design, the functionality of the counter can be expanded to include both counting up and counting down. The DN/UP control line serves as the mode selector, determining the counting direction based on its voltage level. When the DN/UP line is low, the counter increments its value with each clock pulse applied to the A IN input. Conversely, when the DN/UP line is high, the counter decrements its value.
To achieve the maximum counting range of 0 to 15, it is essential to connect the QA output to the BIN input, ensuring that the counter operates within its defined limits. The reset input plays a crucial role in managing the counter's state. When activated (high), it disables the counting process and resets the outputs to a defined state. In up-count mode, the outputs reset to 0, while in down-count mode, they reset to 15. For the counter to function normally, the reset input must remain low, allowing for continuous counting.
Cascading multiple 7493 counters is straightforward and enables the creation of larger counting systems. By connecting the Qv output of one counter to the clock input of the next, a seamless transition of counting can occur, expanding the overall counting range and functionality. This cascading technique is particularly useful in applications requiring higher binary counts, such as digital clocks, frequency dividers, and other sequential logic circuits.One can transform an ordinary binary counter, such as a 7493, into an up/down counter with mode control by adding XOR gates 7486 to the counter"s outputs. The circuit counts up when the DN/UP line is low and down when the DN/UP line is high. To use the 7493 counter to count out its maximum count length of 0 -15, connect the QA output to the BIN input and apply clock pulses to the A IN input.
The reset input, when high, inhibits the count inputs and simultaneously returns the outputs Ao through Do to low in the up-count mode or 15 in the down-count mode. For normal counting, the reset input must be low. One can easily cascade this counter by feeding the Qv line to the clock input of a succeeding counter.
🔗 External reference