CSTEP Examples

Architectural partitioning, guiding CSTEP, EMUCS and Busser, and a fifth-order digital elliptic wave filter example. 

Architectural partitionii, g ding CSTEP, EMUCS and Busser, a fifth-order digital elliptic wave filter example, a Kalman filter example, the BTL310, an ADPCM, the MCS6502, and the IBM System/370. 

CSTEP supports interface timing constraints which specify minimum and maximum times between operations. Constraint declarations in CSTEP describe a constraint name, a time interval between operators, and an inequality with a constant that is expressed in either nanoseconds or clock periods. For example, the following maximum-time constraint specifies that operator xl must execute at least 80ns before operator x2 ... 

Timing constraints and control flow. Timing constraints may be placed on any pair of operators in a behavioral specification. Evaluation of timing constraints must consider the possibility that two operations may be separated by conditionals and loops. In the case of conditionals, there may be more than one path of execution between the two operators. For example. Figure 5-4 shows two operations separated by a single IF-THEN-ELSE conditional construct. Since the two parts of the conditional may take different amounts of time to execute, any timing constraint on the two operators must be satisfied when either of the two paths is executed. When conditionals are nested, additional paths of execution are possible. CSTEP deals with this possibility in a preprocessing step that enumerates the paths between operators and creates a separate constraint for each path. 

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