From d02e5fde91eda2cf083ea306cbfd82777828948c Mon Sep 17 00:00:00 2001 From: Jet Hughes Date: Sat, 16 Jul 2022 11:37:51 +1200 Subject: [PATCH] vault backup: 2022-07-16 11:37:51 --- content/notes/02-combinatorial-logic.md | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/content/notes/02-combinatorial-logic.md b/content/notes/02-combinatorial-logic.md index 3a3453f10..1d3bb8fd6 100644 --- a/content/notes/02-combinatorial-logic.md +++ b/content/notes/02-combinatorial-logic.md @@ -11,6 +11,10 @@ sr-ease: 250 - [slides](https://blackboard.otago.ac.nz/bbcswebdav/pid-2954102-dt-content-rid-18888626_1/courses/COSC204_S2DNI_2022/L2%20-%20Combinatorial%20Logic.pdf) +# Circuit basics: +- current flows + to - +- input to a unit (e.g., LED) is the + end + # Combinatorial Logic Circuit > [!Definition] > Combinatorial Logic Circuit is a circuit whose digital outputs are dependent only on its digital inputs @@ -41,22 +45,27 @@ Precedence ![Precedence table|200](https://i.imgur.com/jPlrVwW.png) -De Morgan's Theorum -- (͞A͞+ B) = Ā · B̄ -- - Creating boolean equations: - for each row where output is 1 - write the equation as a function of the inputs (using AND) - Write the final equation, putting OR between each clause - [example](https://i.imgur.com/RoBTEfH.png) +# De Morgan's Theorum +- !(A + B) = A! & !B +- !(A + B + C + ... + X) = !A & !B & !C & ... & !X +- [truth table](https://i.imgur.com/QegVxkx.png) +- any boolean function can be represented as the sum of logical products +- All combinatorial circuits can be described using just one gate type (either nand or nor) [^2] +# Transistors +![simple transistor diagram|100](https://i.imgur.com/oBuNR9m.png) +- B: Base ⇒ A swtich connecting C to E + - c +- C: Collector +- E: Emitter -# Circuit basics: -- current flows + to - -- input to a unit (e.g., LED) is the + end # Logic Gates - NOT @@ -70,3 +79,4 @@ Creating boolean equations: [^1] : In real circuits propagation delay must be considered, hence the clock cycle on CPUs +[^2] : The Apollo Guidance Computer used about 5600 NOR gates and no other gate types! \ No newline at end of file