MSCCMD_RTSMask
ms->Command = (ms->Command & (~MSCCMD_RTSMask & ~MSCCMD_Enable)) | newcmd;
ms->Command = (ms->Command & (~MSCCMD_RTSMask)) | MSCCMD_Break;
ms->Command = (ms->Command & (~MSCCMD_RTSMask)) | MSCCMD_RTSOn;