| Sequential circuits: state | |||||||||||||
| Mathematical functions have no state: inputs combined to produce output, no memory | |||||||||||||
| C/C++ functions may have state: store data from 1 call to another | |||||||||||||
| static variables | |||||||||||||
| objects store values in data members | |||||||||||||
| State of a running program | |||||||||||||
| Values of variables | |||||||||||||
| Values of registers | |||||||||||||
| Contents of stack | |||||||||||||
| Address of current instruction | |||||||||||||
| Hibernate laptop | |||||||||||||
| Save state of entire machine, including all programs | |||||||||||||
| Sequential logic circuits | |||||||||||||
| Previous history is used together with inputs to produce output | |||||||||||||
| We don't care HOW previous value was obtained | |||||||||||||
| State encoded in bits | |||||||||||||
| Finite number of bits, so finite number of states | |||||||||||||