EMCU is a micro-processor based on ARM Cortex-M3 embedded in the
GW1NSR-4C chip used in the Tangnano4k board.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
We add a BANDGAP primitive used to turn off power to OSC, PLL and other
things on some GOWIN chips.
We also mark this primitive and GSR as keep.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>