Interrupt Latency Counter

Medium C Timing Asked at Infineon

Measure worst-case interrupt latency using a free-running hardware counter. Record the maximum gap between the hardware event timestamp and the moment the ISR body starts.

Constraints

`void isr_entry(uint32_t event_ts)` is called at the top of the ISR.
`uint32_t worst_latency(void)` returns the maximum observed latency in ticks.
The counter is 32-bit and wraps; wrap-around must not produce a bogus huge value.
Use the provided `uint32_t read_counter(void)`.
No 64-bit arithmetic.

Starter codeC

1#include <stdint.h>2 3extern uint32_t read_counter(void);4 5void isr_entry(uint32_t event_ts);6uint32_t worst_latency(void);