A minimal clone of a programmable interrupt timer. Inspried by the Intel 8253 but without most of the features or headaches. See the README.md for detailed documentation.
set input pins to 0x00. pull write enable high, address line 0 low, address line 0 low. set input pins to 0x10, pull write enable high, address line 0 low, address line 1 high. pull bidi pin 3 (timer_start) high, count 10 clock cycles and see if the interrupt pin has pulled high for 1 cycle
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | config[0] - use a clock divider | divider on? | /we write enable for config |
| 1 | config[1] - repeat the interrupt? | counter set? | set config address 0 |
| 2 | config[2] | pit active? | set config address 1 |
| 3 | config[3] | pit in reset? | start the timer |
| 4 | config[4] | pit currently interrupting? | |
| 5 | config[5] | f | |
| 6 | config[6] | g | |
| 7 | config[7] | h |