eldo_user

Examples
Example 25—Setting up and Handling Analog Busses
Tip
Refer to the .SIGBUS, .PLOTBUS, .SETBUS, and .CHECKBUS commands in the Eldo
Reference Manual.
Summary of Eldo commands used in this example:
• .INCLUDE—Library file.
• .SETBUS—Create a bus.
• .SIGBUS—Set signals on a bus.
• .PLOTBUS—Plot bits of a bus.
• .CHECKBUS—Check bus values.
Netlist Explanation
.include bsim46.lib
The above line includes the contents of the library file bsim46.lib in the netlist.
.SETBUS A A
The above line defines a bus A as the vector a.
.SIGBUS A
+ vhi=ps vlo=0
+ base=dec signed=2comp
+ trise=trf tfall=trf thold=per
+ pattern 1 3 5 4 0 -2 -5 2 3 5 6 -1
The A input bus is generated using a .SIGBUS command with the following:
• The bits of the bus toggle between vlo and vhi.
• The rise/fall times and period are defined with trise, tfall and thold.
• The bus values will be given in decimal, and the coding will be in 2’s complement.
• Finally the successive values of the bus are given with the pattern keyword.
.SETBUS B B
.SETBUS S S
The above lines define busses B and S:
.PLOTBUS A VTH=0.6 BASE=DEC RADIX=2COMP
.PLOTBUS B VTH=0.6 BASE=DEC RADIX=2COMP
.PLOTBUS S VTH=0.6 BASE=DEC RADIX=2COMP
The above lines plot the busses, using half/vdd as the threshold, in decimal notation.
1338
Eldo® User's Manual, 15.3