[sdiy] moog module designs

[Scott Gravenhorst]

My bad.  I see it now.  It's fine.

music.maker at gte.net wrote:
>ASSI <Stromeko at Compuserve.DE> wrote:
>>Hi Tim, Scott,
>>
>>On Samstag, 23. April 2005 20:11, Scott Gravenhorst wrote:
>>> Looking at this again, I disagree that this truth table correctly
>>> shows what happens with J and K both high.  if X means "don't care",
>>> then the table is ambiguous.  i.e., for J=H and K=X, what of X is
>>> high? then J=H, K=H and Q=H.  Now look at J=X and K=H.  If X is H,
>>> then J=H and K=H and then Q is LOW?  That conflicts with the first
>>> statement.
>>
>>you are losing me here. Just write out the X explicitly as H and L and 
>>keep the lines with J and K both high:
>>
>>J	K	Q 	-> 	Q	Q'
>>
>>H	H	L		H	L
>>H	H	H		L	H
>
>Yeah, I get this, but you're _adding_ a dependancy on Q that is not
>present in the ST Micro datasheet.  It has input columns for J and K and
>an output column (so labeled) for Q.  Philips describes this behavior
>better IMHO by doing it on one line as:
>
>inputs     output
>J  K       Q
>-----------------
>H  H       not Q
>
>
>
>>When J and K are both H (and S and R both L), then the next output 
>>depends only on the previous Q, more specifically it toggles.
>>
>>> Thats what bit me. If J is high the IC doesn't care what K is at, its
>>> going to put a high out the Q output.
>>
>>No, it's going to put out Q'.
>
>I don't read it that way, it doesn't cite the dependancy on Q.  Philips
>does by stating that Q = invert Q after the clock edge.  So to me, the
>ST truth table is ambiguous.  I'm looking at the PDF right now, I don't
>see any indication that one should consider J, K _and_ Q as 3 input
>logical expression.
>
>
>>> This means that I'll have to expand my lab IC notebook to include
>>> datasheets for multiple versions of standard parts. And my wife
>>> wonders why I don't want to work electronics proffesionally anymore.
>>
>>The datasheet is correct and the truth table expands to a normal JK 
>>flip-flop.
>>
>>On Samstag, 23. April 2005 19:17, Scott Gravenhorst wrote:
>>> Thanks again, I looked at their data sheet, the internal schematic
>>> isn't even close to the Philips sheet.
>>
>>They use a transfer gate D-FF instead of the RS-FF that you seem to 
>>expect, which isn't exactly uncommon in CMOS. This leads to the input 
>>circuitry shown in the data sheet (check any textbook for the 
>>transformations between different FF types).
>>
>>> The ST Micro abortion has a 
>>> J-K input circuit that cannot possibly ever consider the logic state
>>> of both J and K inputs being high.
>>
>>It can. Whatever was wrong with the '4027 that Tim used it, wasn't the 
>>data sheet. I'd suspect the culprit with the setup and hold times if 
>>the problem is specific to the ST part.
>
>Ok, I get this, my problem is of a semantic nature with the way the
>truth table is presented.  It is my contention that the data sheet
>should be indicating a dependancy on Q and it clearly does not say that.
> It works only when you know enough to assume the dependancy on Q and I
>think that's righteously lame.
>
>
>>
>>Achim.
>>-- 
>>+<[Q+ Matrix-12 WAVE#46 Neuron microQkb Andromeda XTk sonic heaven]>+
>>
>>Factory and User Sound Singles for Waldorf Q, microQ and rackAttack:
>>http://Stromeko.Synth.net/#WaldorfSounds
>>
>
>---------------------------------------------------------
>- Where merit is not rewarded, excellence fades.
>- Hydrogen is pointless without solar.
>- What good are laws that only lawyers understand?
>- The media's credibility should always be questioned.
>- The only good terrorist is a dead terrorist.
>- Governments do nothing well, save collect taxes.
>
>-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>-- Linux Rex         | RedWebMail by RedStarWare
>-- FatMan: home1.gte.net/res0658s/fatman/
>-- NonFatMan: home1.gte.net/res0658s/electronics/
>-- Autodidactic Master of Arcane and Hidden Knowledge.
>

---------------------------------------------------------
- Where merit is not rewarded, excellence fades.
- Hydrogen is pointless without solar.
- What good are laws that only lawyers understand?
- The media's credibility should always be questioned.
- The only good terrorist is a dead terrorist.
- Governments do nothing well, save collect taxes.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- Autodidactic Master of Arcane and Hidden Knowledge.