Applets utilization


Generalities

The applets are generally fitted with a "dashboard" that includes all the controls. The pictures of this page come in pair. The upper one is an animated image and the lower an applet. To train yourself, you may reproduce the animation with the applet.

Modification of the input values

The values of A, B or S are modified either by typing a number in the corresponding window and then validating with the "enter" key or by clicking on a bit.
Remarks: Validating two times the same input starts the simulation and the "tab" key passes the cursor to the next window.
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Modification of the number of bits

 The number of bit can be set either by typing a number in the "Nb. bits" window and validate, or by modifying this number with the arrows . One of the two arrows vanishes when a limit is attained. The number of bits modification changes the values of A or B whenever a bit '1' appears or disappears.
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Simulation of the arithmetic operator

 The blue button starts the simulation and stays down until the circuit has settled. The delay displayed during the simulation counts up the number of cell crossing (unit cell delay) and the activity records the output bits changes. Pushing the blue button with the "ctrl" key down restores the circuit in the state before the simulation (undo).
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Views of the operator

The arrow "view " displays another view of the operator. Here it shows how the operator deals with signed or unsigned integers and how the truncation of s8 may result in an overflow (200 + 75 ¹ 19)
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VHDL synthesis

The button "VHDL" opens a window with the operator VHDL description. The code may be copied in the clipboard and pasted in a text editor. Long descriptions are cut into smaller fragments; the key "window/next" passes to the next fragment.
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Cell selection

Clicking inside a cell select the cell and displays its name. Clicking on the right outside the cell deselect it.
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