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Small PLD for interrupt flag register

Hi guys.

Just wondering whether someone could suggest a small PLD which would
be able to fit my design for a 16-bit wide interrupt flag register.
I'm hoping for a DIP package, but I suppose PLCC will do. Not keen on
hand soldering surface mount.

The design consists of 16 input pins going into the J inputs of 16 JK
flip flops. K inputs are unused. The 16 Q outputs go to a 16-1 mux
whose single output goes to an output pin. The 16 CLR inputs go to a
1-16 demux whose enable input goes to an input pin. The select lines
of the mux & demux are connected and brought to 4 input pins. Finally
the 16 input pins also go to a 16 input OR gate whose output goes to
an output pin.
 
Hi guys.

Just wondering whether someone could suggest a small PLD which would
be able to fit my design for a 16-bit wide interrupt flag register.
I'm hoping for a DIP package, but I suppose PLCC will do. Not keen on
hand soldering surface mount.

The design consists of 16 input pins going into the J inputs of 16 JK
flip flops. K inputs are unused. The 16 Q outputs go to a 16-1 mux
whose single output goes to an output pin. The 16 CLR inputs go to a
1-16 demux whose enable input goes to an input pin. The select lines
of the mux & demux are connected and brought to 4 input pins. Finally
the 16 input pins also go to a 16 input OR gate whose output goes to
an output pin.

Too many output blocks for a small pld but your design is easily
splittable so you could get it into two 22v10 dips.
 
U

Uwe Bonnes

Jan 1, 1970
0
Too many output blocks for a small pld but your design is easily
splittable so you could get it into two 22v10 dips.

For small task a XC9536XL comes handy, is in circuit reprogrammable and
below 1 Euro. Why stil bother with PLDs?
 
B

Ben Jackson

Jan 1, 1970
0
Just wondering whether someone could suggest a small PLD which would

Any small CPLD will probably do. Download either Xilinx's WebPack
or Altera's Quartus II web edition and implement your design. You
can do it with schematic capture exactly from your description. It
will then tell you what CPLD will fit the design (probably the
smallest possible thing, like an XC9536 or EPM3064).

PLCC pins are wider, but I'd rather put down a TQFP which keeps the
pins where I can see them. If you bridge a TQFP pin, it's easy to
fix with solder wick. If you bridge a PLCC pin it can be a huge pain
in the ass.
 
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