The counter can count from 0 to 99 and count down from 99 to 0 . Once the reset button is pressed, the counter will reset to 00. If the counter counts from 0 to 9, one of the seven-segment displays should not display any character.
Hint: The control circuit contains 2 decade counters and 2 decoders.
If you all have any circuit diagram , please post it , or also can teach me how should i do. Thank you very much.
The counter can count from 0 to 99 and count down from 99 to 0 . Once the reset button is pressed, the counter will reset to 00. If the counter counts from 0 to 9, one of the seven-segment displays should not display any character.
Hint: The control circuit contains 2 decade counters and 2 decoders.
If you all have any circuit diagram , please post it , or also can teach me how should i do. Thank you very much.
Thank you very very much , ermmm.....can i ask something ? If i don wan use 74LS14 ,i just want using simple logic gates...like OR, AND, NOT, NOR, NAND gates, can i solve it ? Need any calculation ? How to do?
Thank you very very much , ermmm.....can i ask something ? If i don wan use 74LS14 ,i just want using simple logic gates...like OR, AND, NOT, NOR, NAND gates, can i solve it ? Need any calculation ? How to do?
As this is a homework assignment, it is not fair to you for us to do all the work. The samples Eric has given you should give you enough hints to complete it. Do you have the datasheets for the 74LS47 and the 74190? You can download them here **broken link removed**
Read them! Knowing the chips is the first step in designing with them.
If you are using switches for your count and reset inputs, then they have to be debounced. The circuit Eric used with a Schmidt trigger is the simplest available. There are many other solutions, but they involve more chips. The 74LS14 is a simple logic gate. It is a NOT gate. The only difference is that it doesn't have an analog region of operation. In other words it is pure logic. Google "debounce schematic" if you MUST use other logic.
Your up/down switch doesn't need debounce. Just make sure you wait at least 20mS after switching it before you press the count button ;-).
As this is a homework assignment, it is not fair to you for us to do all the work. The samples Eric has given you should give you enough hints to complete it. Do you have the datasheets for the 74LS47 and the 74190? You can download them here **broken link removed**
Read them! Knowing the chips is the first step in designing with them.
If you are using switches for your count and reset inputs, then they have to be debounced. The circuit Eric used with a Schmidt trigger is the simplest available. There are many other solutions, but they involve more chips. The 74LS14 is a simple logic gate. It is a NOT gate. The only difference is that it doesn't have an analog region of operation. In other words it is pure logic. Google "debounce schematic" if you MUST use other logic.
Your up/down switch doesn't need debounce. Just make sure you wait at least 20mS after switching it before you press the count button ;-).
Ok , i done the 2 digit counter circuit already , can you teach me or give me some information how to add reset button in circuit ? Need any calculation ? you no need show me ,just teach me , i will do myself . Thank you very much .
Ok , i done the 2 digit counter circuit already , can you teach me or give me some information how to add reset button in circuit ? Need any calculation ? you no need show me ,just teach me , i will do myself . Thank you very much .
I think i not going to use 74 LS 14 gate to make reset button , got another method ? And , please teach me how to get it ,cause my lecturer will ask later .Thank you.
thanks , the output should connect to both load input right ? Actually i know RS flip -flop is a reset button , but why i cannot get RS flip-flop in multisim ? i checked all the 74 series ,but don have ,or RS flip-flop not in 74 series?