Difference between revisions of "PAL (Chip)"
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that are covered by that bar, the corresponding input is considered as 1 (high). | that are covered by that bar, the corresponding input is considered as 1 (high). | ||
| − | First the PAL takes the Red Blue and Green inputs and uses it to point at a certain square in the map. Whatever the value inside that square is, will be the output of the PAL. | + | First the PAL takes the Red Blue and Green inputs and uses it to point at a certain square in the map. Whatever the value inside that square is, will be the output of the PAL. The first square is only pointed to if no buttons are pressed at all. |
[[File:PAL Color Map.png|thumb]] | [[File:PAL Color Map.png|thumb]] | ||
[[Category:Digital chips]] | [[Category:Digital chips]] | ||
Revision as of 15:36, 31 August 2018
A Programmable Array Logic (PAL) is a programmable logic device semiconductors used to implement any logic function in only one digital circuit. The function is stateless, which means that no intermediate state is saved.
PAL devices consisted of a small PROM (programmable read-only memory) core and additional output logic used to implement particular desired logic functions with few components.
You can use PALs in order to implement any logic function you might need. The PAL chip offers an UI where it's logic function can be programmed very simple. The programming is made using a Karnaugh map. Basically you can specify for each possible state of the three inputs (2 ^ 3 = 8) the resulting output value. All 3 inputs are represented by bars and for all cells in the map that are covered by that bar, the corresponding input is considered as 1 (high).
First the PAL takes the Red Blue and Green inputs and uses it to point at a certain square in the map. Whatever the value inside that square is, will be the output of the PAL. The first square is only pointed to if no buttons are pressed at all.
