常見buffer類型

■ Input Buffer

B_INPUT nd_pc nd_gc nd_in nd_out_of_in
+ file='filename' model='model_name'
+ [typ={typ|min|max|fast|slow}] [power={on|off}]
+ [buffer={1|input}]
+ [interpol={1|2}]
+ [nowarn]
+ [c_com_pc=c_com_pc_value]
+ [c_com_gc=c_com_gc_value]
+ [pc_scal=pc_scal_value]
+ [gc_scal=gc_scal_value]

當power=on(default)時，pc/gc將會使用ibis model里面的電壓值來連接電源，不需要額外再接電壓源；反之，這需要外接電壓源。

buffer測量并處理nd_in的電壓值，并給nd_out_of_in發一個響應，上圖中的V_out_of_in是一個數字信號，根據V_in(Vinh/Vinl/電壓極性)來，有0/0.5/1三個值：

■ Output Buffer

B_OUTPUT nd_pu nd_pd nd_out nd_in [nd_pc nd_gc]
+ file='file_name' model='model_name'
+ [typ={typ|min|max|fast|slow}] [power={on|off}]
+ [buffer={2|output}]
+ [xv_pu=state_pu] [xv_pd=state_pd]
+ [interpol={1|2}]
+ [ramp_fwf={0|1|2}] [ramp_rwf={0|1|2}]
+ [fwf_tune=fwf_tune_value] [rwf_tune=rwf_tune_value]
+ [nowarn]
+ [c_com_pu=c_com_pu_value]
+ [c_com_pd=c_com_pd_value]
+ [c_com_pc=c_com_pc_value]
+ [c_com_gc=c_com_gc_value]
+ [pu_scal=pu_scal_value]
+ [pd_scal=pd_scal_value]
+ [pc_scal=pc_scal_value]
+ [gc_scal=gc_scal_value]
+ [rwf_scal=rwf_scal_value]
+ [fwf_scal=fwf_scal_value]
+ [spu_scal=spu_scal_value]
+ [spd_scal=spd_scal_value]

■ Tristate Buffer

B_3STATE nd_pu nd_pd nd_out nd_in nd_en [nd_pc nd_gc]
+ file='file_name' model='model_name'
+ [typ={typ|min|max|fast|slow}] [power={on|off}]
+ [buffer={4|three_state}]
+ [xv_pu=state_pu] [xv_pd=state_pd]
+ [interpol={1|2}]
+ [ramp_fwf={2|1|0}] [ramp_rwf={2|1|0}]
+ [fwf_tune=fwf_tune_value] [rwf_tune=rwf_tune_value]
+ [nowarn]
+ [c_com_pu=c_com_pu_value]
+ [c_com_pd=c_com_pd_value]
+ [c_com_pc=c_com_pc_value]
+ [c_com_gc=c_com_gc_value]
+ [pu_scal=pu_scal_value]
+ [pd_scal=pd_scal_value]
+ [pc_scal=pc_scal_value]
+ [gc_scal=gc_scal_value]
+ [rwf_scal=rwf_scal_value]
+ [fwf_scal=fwf_scal_value]

■ Input/Output Buffer

B_IO nd_pu nd_pd nd_out nd_in nd_en nd_out_of_in [nd_pc
nd_gc]
+ file='file_name' model='model_name'
+ [typ={typ|min|max|fast|slow}] [power={on|off}]
+ [buffer={3|input_output}]
+ [xv_pu=state_pu] [xv_pd=state_pd]
+ [interpol={1|2}]
+ [ramp_fwf={2|1|0}] [ramp_rwf={2|1|0}]
+ [fwf_tune=fwf_tune_value] [rwf_tune=rwf_tune_value]
+ [nowarn]
+ [c_com_pu=c_com_pu_value]
+ [c_com_pd=c_com_pd_value]
+ [c_com_pc=c_com_pc_value]
+ [c_com_gc=c_com_gc_value]
+ [pu_scal=pu_scal_value]
+ [pd_scal=pd_scal_value]
+ [pc_scal=pc_scal_value]
+ [gc_scal=gc_scal_value]
+ [rwf_scal=rwf_scal_value]
+ [fwf_scal=fwf_scal_value]
+ [spu_scal=spu_scal_value]
+ [spd_scal=spd_scal_value]

eg1：output driver buffer

b_out1 nd_pu nd_pd out1 in1
+ file = 'at16245.ibs'
+ model = 'AT16245_OUT'

eg2：使用ibis component

* Instantiate an IBIS component to see the logical nodes created
.ibis ddr256
+ file ='hyb256_400.ibs'
+ component ='hyb25d256'
.tran 1n 5n
.option post probe dcstep=1
.probe v(ddr*)
.end