Ypsilon.Emulation.Processor.YCPU.STX C# (CSharp) Method

        private void STX(ushort operand)
        {
            int sp_delta = (sbyte)((operand & 0xff00) >> 8);
            if (PS_S) {
                SSP = (ushort)(SSP + sp_delta * 2);
            }
            else {
                USP = (ushort)(USP + sp_delta * 2);
            }
        }