SK_RAMCTL
CSR_WRITE_4(l, SK_RAMCTL, 2); /* enable RAM interface */
sk_win_write_1(sc, SK_RAMCTL, SK_RAMCTL_UNRESET);
sk_win_write_1(sc, SK_RAMCTL + (SK_WIN_LEN / 2), SK_RAMCTL_UNRESET);
sk_win_write_4(sc, SK_RAMCTL, SK_RAMCTL_UNRESET);