BitFlow Cyton-CXP, Справочник по аппаратуре

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Timing Sequencer Introduction
Version A.0 BitFlow, Inc. CYT-4-1
Timing Sequencer
Chapter 4
4.1 Introduction
This section covers the Timing Sequencer (TS) which is currently only available on the
Cyton-CXP. The TS is a sophisticated programmable pulse generator. The TS takes the
place of the NTG on previous models of BitFlow frame grabbers.
The TS improves on the NTG in the following ways:
Driven by an “nice” clock frequency clock so that “normal” pulse sizes and periods
can easily be reproduce (for example 1 micro second pulse every 10 millisec-
onds)
Higher accuracy signals, granularity down to 100 nanoseconds
Supports complex pulse trains of different lengths
Provides synchronize method to switch from one pulse sequence to another
Can be reprogrammed while being used (with some restrictions)
Supports triggering at arbitrary points in a pulse train
4.1.1 Description
TS Table
The TS is programmed through the TS registers. The sequence of pulse that the TS
will put out is programmed by building up “instructions” in the TS table. The table can
hold up to 256 instructions, which can create extremely complex signals. The TS Table
is programmed indirectly via address/data type registers. Once the table is pro-
grammed it can be run at any time via the TS control registers.
Building Pulses
The TS was design to support a wide range of pulse lengths. At the same time, the TS
was design to be able to create pulses of very accurate duration. The solution to these
two apposing problems is to build up a pulse of a desired length via multiple sub-
pulses, each sub-pulse programmed with a different granularity. The following granu-
larities are available:
100 seconds
100 milliseconds
100 microseconds
100 nanoseconds
Each sub pulse can have a length of 1 to 1023 units, where the units are selected from
the list above.