Decoder with many output combination

Question

Is there anyone there that has knowledge if such IC exist? i search in the internet for years like on distributors etc but somehow I can't see any (maybe i don't know the right term or keyword for it to pop-up on search engines).

Only 1 decoder i know that has many output combination and that'll be the decoder for 7 segment only. The rest decoders have only 1 output (e.g 3 to 8 decoder, 1 output H/L and 7 output opposite on the former).

i somehow want to have a decoder flexible enough let's say a 2 to 4 decoder where it can have output combination of:

• LLLL
• HLLL
• HHLL
• HHHL
• HHHH
• LHHH
• LLHH
• LLLH
• HLHL
• HLHH
• HHLH
• LHLL
• LLHL

as i said, all decoders i had searched out (even not dmx-based) have the combination output of only this:

• LHHH
• HLHH
• HHLH
• HHHL

or vice versa.

Aside from shift register, what else could do this kind of combination output that is a decoder and what exactly the term used for these kind of decoders.

• HandyHowie: What are you trying to do?
• jonk: You provided 13 output combinations using 2 inputs posing only 4 selection permutations? Pretty fancy compression you have. Also, the first bunch of them in sequence looks an awful lot like a twisted (Johnson) ring counter to me.
• Mheruian: i am planning to control +60 SPI devices and since i can only control them 1 at a time (1 SPI controller/Master only on a uC), i want to have +60 slave selects. My uC has 12-15 pins only so i have in mind to achieve this is by decoders/multiplexer, i even resort on i/o expanders but they are same as shift registers but uses SPI so i can't resort to that. Though shift registers would do, i still want to know & use a decoder if such exist.
• Mheruian: @jonk :D thanks, never knew that johnson ring counter, going to check it out.
• jonk: The PIC16F57 and PIC16F59 make great i/o expanders. Cheap too. Plus, you can code them so they do whatever you want. But I don't see the problem. If you have to use individual select wires, just use standard decoders and chain them together. Like the 74154. If you want 64 selects, that is four 74154 plus half a 74139. You use up six io pins for selection. If you don't like that, use the PICs I mentioned and send the address serially. Then just two or three io pins.

Answer 1

Aside from shift register, what else could do this kind of combination output that is a decoder and what exactly the term used for these kind of decoders.

If you need a large logic device capable of providing decoded outputs for various combinations of inputs I'd consider an FPGA (field programmable gate array).

• Mheruian: :D thanks for the help Andy, i would look into this FPGA, first time hearing this one.
• Andy aka: @Mheruian everyone is using them these days it seems. Steep learning curve so make sure you understand the cell structure and the programmable interconnect limitations but if you are keen on sweeping up glue logic and/or operating at frequencies that glue logic is incapable of then it’s gonna be for you.