Trace Modes

BitScope performs data capture according to a selected trace mode.

The trace mode controls how many analog channels to capture and what type of timebase to use. It also applies an optional pre and/or post trigger delay to allow data before and/or after to trigger to be captured.

Five registers are used to program the trace mode:

R8 Trace Register Trace mode selection.

R11 Post Trigger Delay Delay after trigger (low byte).

R12 Post Trigger Delay Delay after trigger (high byte).

R13 Time-base Expansion Time-base expansion factor.

R20 Pre-Trigger Delay Buffer prefill before trigger.

The most important trace mode register is the Trace Register R8. The low 4 bits of this register are programmed to with a Trace ID to select one of 6 available modes:

ID Mode Channels Trigger

TM0 Simple Trace Mode Single Channel Level Trigger.
TM1 Simple Trace Mode Dual Channel (Chop) Enhanced Trigger.
TM2 Time-base Expansion Single Channel Enhanced Trigger.
TM3 Time-base Expansion Dual Channel (Chop) Enhanced Trigger.
TM4 Slow Clock Mode Dual Channel (Chop) Enhanced Trigger.
TM8 Frequency Measurement N/A N/A

ID	Mode	Channels	Trigger
TM0	Simple Trace Mode	Single Channel	Level Trigger.
TM1	Simple Trace Mode	Dual Channel (Chop)	Enhanced Trigger.
TM2	Time-base Expansion	Single Channel	Enhanced Trigger.
TM3	Time-base Expansion	Dual Channel (Chop)	Enhanced Trigger.
TM4	Slow Clock Mode	Dual Channel (Chop)	Enhanced Trigger.
TM8	Frequency Measurement	N/A	N/A

The values to program to the other trace mode registers depend on the selected mode. Also, the upper 4 bits of the Trace Register R8 are reserved and should always be programmed as zero.

R8	Trace Register	Trace mode selection.
R11	Post Trigger Delay	Delay after trigger (low byte).
R12	Post Trigger Delay	Delay after trigger (high byte).
R13	Time-base Expansion	Time-base expansion factor.
R20	Pre-Trigger Delay	Buffer prefill before trigger.