ADDER X-SC Manual do Utilizador descarregar pdf (Página 26)

26 CHAPTER 1. INTRODUCTION TO THE ALLIANCE TOOLS

Figure 1.8: The rwgraph.fsm shown by xfsm.

1.3 BOOG

The BOOG (Binding and Optimizing On Gates) tool maps a behavioral description onto a predeﬁned standard

cell library. As we have shown in one example of the use of ASIMUT this tool is usually used in a second step

of the synthesis process in Alliance. It is used after BOOM. The description optimized by BOOM is the input

of this tool. BOOG builds a boolean network equivalent to the description obtained with BOOM. Then for

each bo olean function of each node of the network it tries to ﬁnd a cell or a set of cells that implements that

function. The result will be a structural description based on the cells of the sxlib library of Alliance. We use

this tool given a command of the following form.

% boog [-hmxold] input_file output_file [lax_f ile]

The options available in BOOG are shown in Table 1.5. When using BOOG it is important to check that

Table 1.5: Options Available for the BOOG Tool.

Option Description

-h

Help mode. Displays possible uses of boog.

-m optim mode

Optimization mode. Can be deﬁned in lax ﬁle, it’s only a shortcut to deﬁne it

on command line. This mode number has an array deﬁned between 0 and 4. It

indicates the way of optimization the user wants. If 0 is chosen, the circuit area

will be improved. On the other hand, 4 will improve circuit delays. 2 is a me dium

value for optimization.

-x xsch mode

Generate a ’.xsc’ ﬁle. It is a color map for each signals contained in output ﬁle

network. This ﬁle is used by xsch to view the netlist. By choosing level 0 or 1

for xsch mo de, you can color respectively the critical path or all signals with delay

graduation.

-o output ﬁle Just another way to show explicitely the VST output ﬁle name.

-l lax ﬁle

Just another way to show explicitely the LAX parameter ﬁle name.

-d debug ﬁle

Generates a VBEdebug ﬁle. It comes from internal result algorithm. Users aren’t

concerned.

the corresponding environment variables are set correctly. The most important ones are MBK CATALIB,

MBK TARGETLIB, and MBK OUTLO. MBK CATALIB gives the paths of auxiliary input ﬁles (the

beahvioral ones). MBK TARGETLIB determines the path of the directory of the selected standard cell

library. Finally, MBK OUTLO gives the output format of the structural description.

1.4 BOOM

The BOOM (BOOlean Minimization) tool is used in the ﬁrst step in the synthesis process of Alliance. It opti-

mizes a behavioral description using an RBDD (Reduced Ordered Binary Decision Diagram) representation of

1 2 ... 21 22 23 24 25 26 27 28 29 30 31 ... 86 87

Sem comentários

ADDER X-SC Manual do Utilizador Página 26