Beginner reg question

[TheGreatNed]

Hi,

If I read and write to a simple reg on the same rising clock edge, is the read value guaranteed to be the old data?

I.e:

Code: [Select]

reg[15:0] myreg = 0;

...


always @ (posedge clk)
begin
  output_reg <= myreg;
  myreg <= myreg + 1;
end

output_reg is guaranteed to be the non-incremented (old) value, right?

[ejeffrey]

Yes and this is true regardless of the order of the statements as long as you use non-blocking assignment i.e. <=. You should always use non blocking assignments in a clocked block.

[TheGreatNed]

Yes and this is true regardless of the order of the statements as long as you use non-blocking assignment i.e. <=. You should always use non blocking assignments in a clocked block.

thank you