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

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.