Answers Database Foundation State Editor F1.x, XABEL: One-hot state machine is created "Cold" Record #3151 Product Family: Software Product Line: Aldec Product Part: Foundation State Editor Product Version: 1.5is2 Problem Title: Foundation State Editor F1.x, XABEL: One-hot state machine is created "Cold" Problem Description: Urgency: Standard General Description: When creating a one-hot state machine through the Foundation State Editor with Abel as the synthesis language, the state machine produced will be "cold", ie, it will never move from the "000" state. Solution 1: The method in resolution 1 provides a workaround to the problem. However, if any further revisions are made to the state diagram, the ABEL code is regenerated, and the initial condition is lost. A way to apply an initial condition which will not be over-written is the following. Write the initial condition in the '//diagram ACTIONS' box at the top of the state editor. Simply double-click on the '//diagram ACTIONS' box, and then on the line below it, write: <INIT_STATE>.AP=0; Solution 2: This problem is caused by the fact that the Abel code is produced with all state registers initializing to 0. This means that the state machine powers up to all 0's, and therefore is not in any state in the one-hot encoded state machine. The workaround is to manually edit the ABEL code such that the code will initialize to the initial-state. To do this, add the following line to the Equations section of the Abel code: <INIT_STATE>.AP = 0; where <INIT_STATE> is the desired initial state. This will force this particular state register to be a "preset" register, and therefore power-up to '1', and therefore the one-hot state machine will be in this state to begin with. End of Record #3151 - Last Modified: 05/28/99 08:01

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