MCF_CCM_CDR_SSIDIV
temp = mcf_read16(MCF_CCM_CDR) & MCF_CCM_CDR_SSIDIV(0xF);
mcf_write16(MCF_CCM_CDR_LPDIV(div) | MCF_CCM_CDR_SSIDIV(temp), MCF_CCM_CDR);