Specifications

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11 reserved.

For example, a simple digital follower is speciﬁed by the bit pattern 01 10, because it sets the output on positive transitions of the

input, and clears the output on negative transitions. A digital inverter is similarily 10 01. These systems have only one sensitive

input.

As another example, a simple up counter, which increments on positive transitions of one input, is speciﬁed by 01 00. This

system has only one sensitive input.

When multiple digital inputs are used, the inputs are divided into two types, inputs which cause changes in the accumulator, and

those that only modify the meaning of transitions on other inputs. Modiﬁer inputs do not require bitﬁelds, but there needs to be a

bitﬁeld of length 4*(2ˆ(N-1)) for each edge sensitive input, where N is the total number of inputs. Since N is usually 2 or 3, with

only one edge sensitive input, the scaling issues are not signiﬁcant.

4.7.2 Analog ﬁltering conﬁguration

(Status: design (i.e., no driver implements this yet).)

The insn ﬁeld of the instruction data structure has not been assigned yet.

The chanspec ﬁeld of the instruction data structure is ignored.

Some devices have the capability to add white noise (dithering) to analog input measurement. This additional noise can then be

averaged out, to get a more accurate measurement of the input signal. It should not be assumed that channels can be separately

conﬁgured. A simple design can use 1 bit to turn this feature on/off.

Some devices have the capability of changing the glitch characteristics of analog output subsytems. The default (off) case should

be where the average settling time is lowest. A simple design can use 1 bit to turn this feature on/off.

Some devices have a conﬁgurable analog ﬁlters as part of the analog input stage. A simple design can use 1 bit to enable/disable

the ﬁlter. Default is disabled, i.e., the ﬁlter being bypassed, or if the choice is between two ﬁlters, the ﬁlter with the largest

bandwidth.

4.7.3 Analog Output Waveform Generation

(Status: design (i.e., no driver implements this yet).)

The insn ﬁeld of the instruction data structure has not been assigned yet.

The chanspec ﬁeld of the instruction data structure is ignored.

Some devices have the ability to cyclicly loop through samples kept in an on-board analog output FIFO. This conﬁg should allow

the user to enable/disable this mode.

This conﬁg should allow the user to conﬁgure the number of samples to loop through. It may be necessary to conﬁgure the

channels used.

4.7.4 Extended Triggering

(Status: alpha.)

The insn ﬁeld of the instruction data structure has not been assigned yet.

The chanspec ﬁeld of the instruction data structure is ignored.

This section covers common information for all extended triggering conﬁguration, and doesn’t describe a particular type of

extended trigger.

Extended triggering is used to conﬁgure triggering engines that do not ﬁt into commands. In a typical programming sequence,

the application will use conﬁguration instructions to conﬁgure an extended trigger, and a command, specifying TRIG_OTHER

as one of the trigger sources.