Swap (cont’d)

always @(posedge CLK) begin A = B; end

always @(posedge CLK) begin B = A; end

always @(posedge CLK) begin A <= B; end

always @(posedge CLK) begin B <= A; end

• The following code executes incorrectly

  • One block executes first
  • Loses previous value of variable

• Non-blocking assignment fixes this

  • Both blocks are scheduled by posedge CLK

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