muzikliberated
Active member
- Joined
- Mar 7, 2013
- Messages
- 33
Hey Guys,
I'm in a bit of a miff finding a suitable Latch IC.
The Problem:
I'm drawing a synth schematic, of which, the filter section has a series of 4066 analog switches which are used to re-configure the filter into different responses.
This part is done, coming out of the filter I just need to set 4 bits A B C D
Now, because there are a total of 8 filter sections, I would really need a lot of GPIO to keep all the filters catered for (I want to be able to control them all independently)
What I came up with so far is to use 4 x CD4508 all hanging off the same data bus and then use a 74HC138 (I know, its' the wrong symbol in the schematic) to select all the individual 4508s and clock in the bits to the filter section 4066 that way.
However, I dont think that's gonna work as I believe that only 1 chips outputs will be active at any one time, and of course, I need these to latch.
I think the 4508s go 'HI Z' so that if the output data is on a bus, only 1 chips outputs will be active at a time, which is backwards from what I want since the outs aren't busses.
I thought I could use the strobe instead of the /EN but that won't work either as the outs follow the ins when strobe is high.
In a pickle... lol
to recap, I have 8 filters, each needs 4 bits to be latched so they can be independently set, I would like to be able to buss the data lines together to save on gpio opting to use separate enable lines.
Any suggestions?
I'm in a bit of a miff finding a suitable Latch IC.
The Problem:
I'm drawing a synth schematic, of which, the filter section has a series of 4066 analog switches which are used to re-configure the filter into different responses.
This part is done, coming out of the filter I just need to set 4 bits A B C D
Now, because there are a total of 8 filter sections, I would really need a lot of GPIO to keep all the filters catered for (I want to be able to control them all independently)
What I came up with so far is to use 4 x CD4508 all hanging off the same data bus and then use a 74HC138 (I know, its' the wrong symbol in the schematic) to select all the individual 4508s and clock in the bits to the filter section 4066 that way.
However, I dont think that's gonna work as I believe that only 1 chips outputs will be active at any one time, and of course, I need these to latch.
I think the 4508s go 'HI Z' so that if the output data is on a bus, only 1 chips outputs will be active at a time, which is backwards from what I want since the outs aren't busses.
I thought I could use the strobe instead of the /EN but that won't work either as the outs follow the ins when strobe is high.
In a pickle... lol
to recap, I have 8 filters, each needs 4 bits to be latched so they can be independently set, I would like to be able to buss the data lines together to save on gpio opting to use separate enable lines.
Any suggestions?