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+---
+title: "sequential-circuits"
+aliases: 
+tags: 
+- cosc204
+---
+
+
+[combinatorial-logic-circuits](notes/combinatorial-logic-circuit.md) always  produce the same outputs given the same input. Sequential curcuits on the other hand, produce different outputs depending on past history and the inputs. 
+
+![combinatorial vs sequential](https://i.imgur.com/GbfAZ4c.png)
+
+There are two main types of sequential circuit
+- Sychronous
+	- this is when changes of state occur in time with a clock cycle
+	- changes of input occur between clock pulses
+	- state changes occur at the clock pulses
+- Asynchronous
+	- state changes occur as the inputs occur
+	- event driven
+
+# Main circuits
+## SR latch
+The set reset latch is the most basic and simple sequential circuit
+
+![sr latch](https://i.imgur.com/mhXd77i.png)
+