Inverting bits
in [DSP]
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From: Vladimir Vassilevsky on 2 Jan 2010 23:45 robert bristow-johnson wrote: > On Jan 2, 1:16 pm, Vladimir Vassilevsky <nos...(a)nowhere.com> wrote: > >>robert bristow-johnson wrote: >> >>>that being said, it sounds like you need a counter. i'm sure someone >>>has a nice compact divide-by-3 counter circuit laying around. it >>>would need at least 2 flip-flops in it. >> >>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>Nope. >> >>There is about a zillion of ways for making N-state flip-flop, i.e. >>flip-flap-flop for 3 states, flip-flap-flup-flop for 4 states, etc. > > > i don't understand what you are referring to by "Nope". was it my > first or second or third statement that was inaccurate? > > just curious. My point is that hardware logic doesn't have to be binary. So it doesn't have to store integer number of bits. I can think of 3-state system from combinatorial logic as well as 3-level semi-analog solutions. VLV
From: Jerry Avins on 3 Jan 2010 00:11 Vladimir Vassilevsky wrote: > > > robert bristow-johnson wrote: > >> On Jan 2, 1:16 pm, Vladimir Vassilevsky <nos...(a)nowhere.com> wrote: >> >>> robert bristow-johnson wrote: >>> >>>> that being said, it sounds like you need a counter. i'm sure someone >>>> has a nice compact divide-by-3 counter circuit laying around. it >>>> would need at least 2 flip-flops in it. >>> >>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>> Nope. >>> >>> There is about a zillion of ways for making N-state flip-flop, i.e. >>> flip-flap-flop for 3 states, flip-flap-flup-flop for 4 states, etc. >> >> >> i don't understand what you are referring to by "Nope". was it my >> first or second or third statement that was inaccurate? > > You don't have to use two flip-flops to divide by 3. A 3-state counter > could be done entirely without flip-flops. Interesting! How? Of course, one can use transistors or even tubes in an appropriate arrangement. It's even possible to do it mechanically, but the 60 MHz requirement makes that difficult and prone to rapid wear. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: robert bristow-johnson on 3 Jan 2010 00:23 On Jan 2, 11:45 pm, Vladimir Vassilevsky <nos...(a)nowhere.com> wrote: .... > My point is that hardware logic doesn't have to be binary. So it doesn't > have to store integer number of bits. I can think of 3-state system from > combinatorial logic as well as 3-level semi-analog solutions. that is the kernel. i did not consider multi-value logic. i remember that was supposed to be the rage in the 80s when i was a grad student. i never saw anything come of it, but i s'pose someone somewhere made use of multivalued logic. it just seems as the B+ voltage drops from 5 volts to 3.3 to even less, that multivalued logic loses its feasibility. and it seems that industry would rather put a zillion "pins" (or pads or balls) on their chips than cut the number in half and use 4-valued logic. r b-j
From: Eric Jacobsen on 3 Jan 2010 00:36 On 1/2/2010 10:23 PM, robert bristow-johnson wrote: > On Jan 2, 11:45 pm, Vladimir Vassilevsky<nos...(a)nowhere.com> wrote: > ... >> My point is that hardware logic doesn't have to be binary. So it doesn't >> have to store integer number of bits. I can think of 3-state system from >> combinatorial logic as well as 3-level semi-analog solutions. > > that is the kernel. i did not consider multi-value logic. i remember > that was supposed to be the rage in the 80s when i was a grad student. > i never saw anything come of it, but i s'pose someone somewhere made > use of multivalued logic. it just seems as the B+ voltage drops from > 5 volts to 3.3 to even less, that multivalued logic loses its > feasibility. and it seems that industry would rather put a zillion > "pins" (or pads or balls) on their chips than cut the number in half > and use 4-valued logic. > > r b-j A lot of the popular FLASH memory technologies are multi-state and the memory cells each store multiple bits (two, IIRC). -- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
From: Vladimir Vassilevsky on 3 Jan 2010 00:38
robert bristow-johnson wrote: > On Jan 2, 11:45 pm, Vladimir Vassilevsky <nos...(a)nowhere.com> wrote: > ... > >>My point is that hardware logic doesn't have to be binary. So it doesn't >>have to store integer number of bits. I can think of 3-state system from >>combinatorial logic as well as 3-level semi-analog solutions. > > > that is the kernel. i did not consider multi-value logic. It doesn't have to be multi-value. It is possible to make 3-state system from conventional _binary_ gates without flip-flops. I.e. you can make ternary flip-flap-flop directly from combinatorial logic. It is 23:30 already and I am not yet finished with the job for today. Will try to put together an example tomorrow. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com |