Difference between revisions of "PAL (Chip)"
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| − | A Programmable Array Logic (PAL) is a programmable logic device semiconductors used to implement | + | A [https://en.wikipedia.org/wiki/Programmable_Array_Logic 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 | any logic function in only one digital circuit. The function is stateless, which means that no | ||
intermediate state is saved. | intermediate state is saved. | ||
Revision as of 00:56, 28 December 2016
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).
Play a little with the 3 buttons and the PAL configuration to see how it works.
Here some examples of standard gates implemented by a PAL:
- AND Gate
| 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 |
- OR Gate
| 0 | 1 | 1 | 1 |
| 1 | 1 | 1 | 1 |
