NGLE_BUSY
stat = gftfb_read1(sc, NGLE_BUSY);
stat = gftfb_read1(sc, NGLE_BUSY);
stat = hyperfb_read1(sc, NGLE_BUSY);
stat = hyperfb_read1(sc, NGLE_BUSY);
volatile uint32_t r = hyperfb_read4(sc, NGLE_BUSY);