Achronix Speedster22i User Macro Guide Bedienungsanleitung PDF herunterladen (Seite 71)

Registers DFFEP

Speedster22i Macro Cell Library

AchronixSemiconductorProprietary PAGE 55

DFFEP

Positive Clock Edge D-Type Register with Clock Enable and

Synchronous Preset

DFFEP

Figure 2-4: Logic Symbol

DFFEPisasi

ngleD‐typeregisterwithdatainput(d),clock enable(ce),clock(ck),andactive‐

lowsynchronouspreset(pn)inputs anddata (q)output. Theactive‐lowsynchronouspreset

inputsetsthedataoutputhighuponthenextrisingedgeoftheclockifitisassertedlowand

the clock enable si

gnal is assertedhigh. If the synchronous preset input is not asserted, the

dataoutputissettothevalueonthedatainputuponthenextrisingedgeoftheclockifthe

active‐highclockenableinputisasserted.

Pins

Table 2-10: Pin Descriptions

Name Type Description

d Data input.

Active-low synchronous preset input.

A low on pn sets the q output high

upon the next rising edge of the clock if the clock enable is asserted high.

ce Active-high clock enable input.

ck Positive-edge clock input.

Data output. T

he value present on the data input is transferred to the q out-

put upon the rising edge of the clock if

the clock enable input is high and the

synchronous preset input is high.

Parameters

Table 2-11: Parameters

Parameter Defined Values Default Value

init 1’b1

init

The init parameter defines the initial value of the output of the DFFEP register.Thisis the

valuetheregistertakesupontheinitialapplicationofpowertotheFPGA.Thedefaultvalue

oftheinitparameteris1’b1.

input

output

1’b0, 1’b1

1 2 ... 66 67 68 69 70 71 72 73 74 75 76 ... 223 224

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Achronix Speedster22i User Macro Guide Bedienungsanleitung Seite 71