question : insert JTAG with BSD compiler

define_dft_design -design U2 -type PAD \
-interface {data_in A h data_out I h \
enable EN h port IO h} \
-params {$pad_type$ string bidirectional\
$lib_cell$ string true }

I specified the "define_dft_design" command below to model the pad.
But BSD compiler only insert BSR in pin I (data_out) , and connect pin A with 1’b0 .
waring information :
An INPUT boundary scan register cell is missing on design port SET_TIME.
information: Input BSR cell is not detected at port SET_TIME beacuse the pad
is not able to propagate data. Values at the pad pins:
U12/I = 0, U12/EN = X, U12/dpad_digio= X,
U12/dvdd = 0, U12/A = X (TEST-1122)

anyone can tell me how to make BSD compiler identify I/O pad . how to make
TAP FSM control I/O enable. thanks a lot