1.Why do we need 555 timer circuit in a parallel input serial output register?

2.A ring counter is also a shift register. In what way does it function as one?

3.Why do we include a RC network to the input of ring counters?

Pls email me or reply to this topic...thanks!

 

Originally posted by Leonid83@Mar 20 2006, 02:50 PM
1.Why do we need 555 timer circuit in a parallel input serial output register?

2.A ring counter is also a shift register. In what way does it function as one?

3.Why do we include a RC network to the input of ring counters?

Pls email me or reply to this topic...thanks!

[post=15220]Quoted post[/post]​

I could swear that I posted a reply to this question and it seems to have disappeared.

1. You do not need a 555 timer circuit in a parallel input serial output register. You do need some kind of clock signal to tell the shift register to shift.

2. In a ring counter the next value of each stage is a function of the previous stage. The last stage is normally inverted and fed back to the input of the first stage. The connection between a ring counter and a shift register is superficial at best.

3. An RC network in a digital context is designed to produce a delayed version of a signal or to provide some minimal amount of noise immunity. This is generally speaking a questionable practice.

Without a diagram of the circuit it can be hard to imagine what the designer had in mind.

 

Originally posted by Papabravo@Mar 20 2006, 03:54 PM
I could swear that I posted a reply to this question and it seems to have disappeared.

1. You do not need a 555 timer circuit in a parallel input serial output register. You do need some kind of clock signal to tell the shift register to shift.

2. In a ring counter the next value of each stage is a function of the previous stage. The last stage is normally inverted and fed back to the input of the first stage. The connection between a ring counter and a shift register is superficial at best.

3. An RC network in a digital context is designed to produce a delayed version of a signal or to provide some minimal amount of noise immunity. This is generally speaking a questionable practice.

Without a diagram of the circuit it can be hard to imagine what the designer had in mind.

[post=15228]Quoted post[/post]​

I understand now, almost identical question posed in two different forums. Tsk...Tsk.