SPRUJ52C june 2022 – july 2023 AM69 , AM69A , TDA4AH-Q1 , TDA4AP-Q1 , TDA4VH-Q1 , TDA4VP-Q1
As noted in above, there are three timings that are critical:
Figure 5-4 shows the sampled POK output to the ESM when the POK threshold is ping-ponged.
In this case, the ESM sees an update of the POK threshold every ( + {4, 8,12,16} + 1) × 1.25[µs]. Since the ESM sees an update of a threshold every ~us to every ~-us, the UV and OV flags are individually being updated every ~-us to every -us.
In the case where the PRG does not ping-pong, a fixed threshold is applied. The deglitch (filter) time can be chosen as {4, 8, 12, 16} 1.25-us clock cycles. The filter is a sliding window that evaluates the filtered output every 1.25-us based upon the last n samples ( n = {4, 8, 12, 16}). In this case, the ESM sees an update of the POK threshold every 1.25 us.
The POKs are sampled by a divided-down CLK_12M_RC (WKUP_RC_OSC_12M from Section 5.4.4.1.2). The sampling clock is nominally 12.5 MHz (though because it is an RC-generated clock, the frequency is not precise). This input clock is divided by 16 so that sampling records the POK output on the rising edge every ~1.25 us.