What is the interrupt latency of a PSoC® 1 device?
Interrupt latency is the time between the assertion of an enabled interrupt and the start of its interrupt service routine (ISR). It is calculated using the following equation:
Latency = Time to finish the current instruction +Time for M8C to change program counter to interrupt address +Time to execut e the LJMP instruction in the interrupt table
For example, if the five-cycle JMP instruction is executing when an interrupt becomes active, the total number of CPU clock cycles before the ISR begins is as follows:
(1 to 5 cycles for JMP to finish) + (13 cycles for interrupt routine) + (7 cycles for LJMP) = 21 to 25 cycles.
In this example, at 24 MHz, 25 clock cycles take 1.042 µs.