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M3i.48xx / M3i.48xx-exp Manual

Combination of Memory Segmentation Options with Timestamps

Timestamps

The BaseXIO-Data sampling option requires the option BaseXIO to be installed. All enhanced timestamps are
no longer sign extended integer 64 values so that before using these stamps for calculations (such as calcu-
lating the difference between two stamps) one has to mask out the leading byte of the stamps first.

Extended BaseXIO incremental encoder counter format

Some applications require to relate the generated timestamps to a rotary position coming from incremental encoders. Therefore this dedicated
timestamp mode provides storage of values from two 10 bit counters (leading to a range from 0 to 1023) with separate „Count“ and „Reset“
lines is provided. This mode requires therefore four external TTL lines which are only available, if the BaseXIO option is installed. Details of
the BaseXIO pinout can be found in the BaseXIO chapter in this manual.
With each rising edge of the count input the counter is incremented by one step. Because that input is synchronized into the internal clock
domain, please make sure that the HIGH and the LOW time are at least 16 times of the sampling period time long. So when sampling with
100 MS/s (10 ns period time) the pulse has at least a length of 160 ns. A HIGH event on the reset line (assertion) will set the counter asyn-
chronously back to zero. The de-assertion of the reset line is synchronized to the same internal clock domain as the count inputs to prevent
runt pulses from corrupting the counter reset.
When enabling the M3i encoder option the total 64 bits of one timestamp are divided up into up to four parts:

Using the incremental encoder counter requires the driver V2.16 (or newer) and the M3i main control firm-
ware version V14 (or newer). Please update your system to the latest versions to run this mode.

clock counter values of the stamps first.

Selecting the timestamp data format

The selection between the different data format for the timestamps is done with a flag that is written to the timestamp command register. As
this register is organized as a bitfield, the data format selection is available for all possible timestamp modes.

Combination of Memory Segmentation Options with Timestamps

This topic should give you a brief overview how the timestamp option interacts with the options Multiple Recording and ABA mode for which
the timestamps option has been made.

Multiple Recording and Timestamps

Multiple Recording is well matching with the timestamp option. If timestamp
recording is activated each trigger event and therefore each Multiple Re-
cording segment will get timestamped as shown in the drawing on the right.

Please keep in mind that the trigger events are timestamped, not the begin-
ning of the acquisition. The first sample that is available is at the time position
of [Timestamp - Pretrigger].

The programming details of the timestamp option is explained in an extra
chapter.

Timestamp Mode

byte

Standard / StartReset

10 bit wide Incre-
mental Counter 1

10 bit wide Incre-
mental Counter 2

44bit wide sample counter

Refclock mode

10 bit wide Incre-
mental Counter 1

10 bit wide Incre-
mental Counter 2

14 bit wide Refclock edge
counter (seconds counter)

30bit wide sample counter

Register

Value

Direction

Description

SPC_TIMESTAMP_CMD

47100

r/w

SPC_TSXIOINC_ENABLE

2000h

Enables the trigger synchronous acquisition of the two 10 bit incremental counters with every stored timestamp in the
upper 20 bit of the timestamp data.

SPC_TSXIOACQ_ENABLE

1000h

Enables the trigger synchronous acquisition of the BaseXIO inputs with every stored timestamp in the upper byte.

SPC_TSXIOACQ_DISABLE

The timestamp is filled up with leading zeros as a sign extension for positive values.