Achronix Speedster22i User Macro Guide Bedienungsanleitung PDF herunterladen (Seite 34)

I/O Cells IPAD_D2

Speedster Macro Cell Library

www.achronix.com PAGE 17

IPAD_D2

DDR Input Pad with Asynchronous or Synchronous Set/Reset

douta

pad

IPAD_D2

rstn

data_en

rstn

clk

doutb

Figure 1-8: IPAD_D2 Logic Symbol

IPAD_D2isaDoubl

eDataRate(DDR)inputpad.Thereisanadditionalregisterstageonthe

inputtoallowthelogiclevelonthe padtochangesonboth therisingandfallingedgesofthe

clock,butallowtheinterfacesignalstoandfromtheFPGAcoretochangeontherisingedge 

oftheclock.Thisadditionallev

elofregistersprovidesafullcycletogetintoandoutofthe

FPGAcore.

Table 1-20: Ports

Name Type Description

pad Bidirectional device pad.

douta

Positive-edge based data output. Da

ta is clocked from the pad to an

internal register on the rising edge of the clock. On the next rising edge of

the clock, if the data_en input is high, the data will appear on the douta

output.

doutb

Negative-edge based data output.

Data is clocked from the pad to an

internal register on the falling edge of the clock. On the next rising edge

of the clock, if the data_en input is high, the data will appear on the doutb

output.

data_en

Receive Data Enable (active-high). A high value on rxdata_en enables the

eceived data to be clocked into the douta and doutb output registers.

rstn

Input Register Reset input. A l

ow value on rstn performs an asynchro-

nous initialization of the Input Register if the

rstmode parameter is set to

“async”. A low value on rstn performs a synchronous initialization of the

input registers if the rstmode parameter is set to "sync". The value initial-

ized into the Input Register is deter

mined by the value of the rstvalue

parameter.

clk Input Register Clock Input.

input

output

input

1 2 ... 29 30 31 32 33 34 35 36 37 38 39 ... 223 224

Kommentare zu diesen Handbüchern

Keine Kommentare

Achronix Speedster22i User Macro Guide Bedienungsanleitung Seite 34

Kommentare zu diesen Handbüchern