EMU_A_DBG
emu_wrptr(sc, 0, EMU_A_DBG, EMU_A_DBG_SINGLE_STEP);
emu_wrptr(sc, 0, EMU_A_DBG, 0);
emu_wrptr(sc, 0, EMU_A_DBG, EMU_A_DBG_SINGLE_STEP);
emu_wrptr(sc, 0, EMU_A_DBG, EMU_A_DBG_SINGLE_STEP);
emu_wrptr(sc, 0, EMU_A_DBG, 0);