Reset Logic Function

[We Ech Dee Ell]

Hi All,

I have some code that consistently gives the problem of "Reset Logic
Function", "Multiple Resets" etc. with some design checking tool for
synthesis.


The code is:
------------------


write_enable : PROCESS (Clock)
BEGIN
IF (Clock'EVENT) AND (Clock = '1') THEN
IF ( Reset = '1' ) THEN
register_we_REG1_i1 <= '0';
Wack <= '0';
ELSIF (WStrobe = '1') THEN
register_we_REG1_i1 <= register_select(0);
Wack <= '1';
END IF;
END IF;
END PROCESS write_enable;

----------------------------------------------------------------
reg_REG1_field16_i1 : PROCESS (Clock)
BEGIN
IF (Clock'EVENT) AND (Clock = '1') THEN
IF Reset = '1' THEN
field16_i1 <= '1';
ELSIF ( register_we_REG1_i1 = '1' ) THEN
field16_i1 <= Wdata(16);
END IF;
END IF;
END PROCESS reg_REG1_field16_i1;


Can someone please help?
Change is sensitivity lists is not allowed. Only synchronous processes
are allowed.


Thanks a lot in advance!

 

[backhus]

Hi All,

I have some code that consistently gives the problem of "Reset Logic
Function", "Multiple Resets" etc. with some design checking tool for
synthesis.

The code is:
------------------

 write_enable : PROCESS (Clock)
  BEGIN
    IF (Clock'EVENT) AND (Clock = '1') THEN
      IF ( Reset = '1' ) THEN
          register_we_REG1_i1 <= '0';
          Wack <= '0';
      ELSIF (WStrobe = '1') THEN
          register_we_REG1_i1 <= register_select(0);
          Wack <= '1';
      END IF;
    END IF;
  END PROCESS write_enable;

 ----------------------------------------------------------------
  reg_REG1_field16_i1 : PROCESS (Clock)
  BEGIN
    IF (Clock'EVENT) AND (Clock = '1') THEN
      IF Reset = '1' THEN
        field16_i1 <= '1';
      ELSIF ( register_we_REG1_i1 = '1' ) THEN
        field16_i1 <= Wdata(16);
      END IF;
    END IF;
  END PROCESS reg_REG1_field16_i1;

Can someone please help?
Change is sensitivity lists is not allowed. Only synchronous processes
are allowed.

Thanks a lot in advance!

Hi,
the code shows some nice examples for FFs with sync. Reset and Clock
Enable functions.
Only thing that looks strange to me is the Wack signal, that never
returns to '0', unless the FF gets resetted.
Once written to the FF, the write acknowledge never becomes inactive?
If not really intended an else branch could fix this.

So, what about the mentioned reset problem?
What messages do you see, printed by what kind of tool?
I can't see a connection between your code fragments and the very
common prased problems.

Have a nice synthesis
Eilert