TM2 - Single Channel Expanded

This trace mode is similar to TM0: it captures data from the primary channel only.

The difference is that the capture sample period is expanded. This time-base expansion operates by enabling data capture for one PIC cycle every P PIC cycles where P is the expanded time-base sample period computed from the Time-base Expansion Register R13 according to:

P = 14 + 3 * (TB + 1)

Pexpanded time-base period (in PIC cycles).
TB 8 bit time-base expansion (R13 -> 1 to 256, 0 read as 256).

The minimum time-base expansion period is 8.0 uS and the maximum 314 uS. This provides expanded time-base sample rates ranging from 3.184 kHz to 125 kHz. At all expanded time-base rates, 10 samples are acquired in a single burst at 25 MHz at each expanded period.

The pre trigger delay is calculated as:


T[PRE] pre trigger delay (in PIC cycles).
PRETD 8 pre trigger delay value (R20 -> 0 to 255).
Pexpanded time-base period (in PIC cycles).

The post trigger delay is calculated as:

T[PTD] = P * N + U

N = PTD + PTD[hi] + 2


T[PTD] post trigger delay (in PIC cycles).
N number of expanded capture periods.
Pexpanded time-base period (in PIC cycles).
PTD 16 bit post trigger delay value (R11, R12 -> 0 to 65536).
PTD[hi] 8 bit high byte of post trigger delay (R11 -> 0 to 255).
U trigger uncertainty = ± 2 PIC cycles

This trace mode supports the use of analog edge trigger logic.