Custom Instruction and ALU

Hi all,

In an embedded project I am developing I have implemented 2 different

custom instructions (in particular 2 "External Interface Custom

Instruction") with a variable Multi-Cycle.

Each custom instruction has the canonical inputs and oputputs as specified in the custom instruction application note:

INPUT: clk, clk_en, reset, start

OUTPUT: done, result[31..0]

Currently, these two custom instructions could be implemented with only

one piece of logic that can serve both instructions.

If I try to implement them with a single piece of logic, I get all the

input and output pins twice (one for the first custom instruction, one

for the second).

Are there any relationship between the first custom instruction's pins and

the second custom instruction's pins inside the ALU???

(For example, I would expect that clk, clk_en, reset, and other pins are simply the same signals routed once for each custom instruction...)

May I simplyfy the hardware I'm writing supposing that some pins arrive

only once to that unique piece of logic that serve more than one custom

instruction?

Thank you!

Matteo