求助:HSPICE输入网标报错的问题

如下，输出显示：**error**sweep format incomplete, not enough arguments
**error** (c:\synopsys\hspice_z-2007.03\14bit_dac\nmos_mirror.sp:14) difficulty in reading input
期望那位大侠告知
sp文件：
.TITLE NMOS current mirror
.lib 'C:\synopsys\Hspice_Z-2007.03\SMIC018\smic18mmrf_1P6M_200902271315\smic18mmrf_1P6M_200902271315\models\hspice\ms018_v1p9.lib' tt
.global vdd
.option probe
M1 3 1 0 0 n18 W=0.18u L=0.18u
M2 1 2 3 3 n18 w=0.18u L=0.18u
M3 4 1 0 0 n18 W=0.18u L=0.18u
M4 out 2 4 4 n18 W=0.18u L=0.18u
Vb 2 0 1.3V
VCC VDD 0 3.3V
Iref VDD 1 0.7uA
.DC Iref VDD 1 1uA 0.05uA
.op
.probe I(out)
.end

直流扫描的步长

直流扫描