According to the latest documentation from GOWIN - "UG285-1.4E Gowin BSRAM & SSRAM User Guide" The dual port BSRAM of all 55nm devices (including GW1N, GW2A and GW1A series) does not support the read-before-write mode (WRITE_MODE = 2) Signed-off-by: YRabbit <rabbit@yrabbit.cyou>