Altera Double Data Rate I/O Bedienungsanleitung PDF herunterladen (Seite 6)

Parameter Description

Use ‘dqsundelayedout’ port Creates undelayed output from the DQS pins. If you

use the ALTDDIO_BIDIR IP core for your DQS

signal in an external memory interface, you route

the undelayed DQS signal to the LE, in Stratix II and

Stratix devices. This option is available in Stratix,

Stratix GX, and HardCopy Stratix devices only.

Use ‘dataout_h’ and ‘dataout_l’ ports Enables the dataout_h and dataout_l ports.

Implement input registers in LEs Implements the input path in logic elements. This

option is available only if the dataout_h and

dataout_l ports are enabled.

ALTDDIO Functional Description

DDR Device Configuration

The following sections describe how the DDR registers are configured in the Stratix series and APEX II

devices.

Input Configuration

When the IOE is configured as an input pin, input registers A

and B

and latch C

implement the input

path for DDR I/O.

Figure 1: Input DDR I/O Path Configuration for a Stratix Series or APEX II Device

This figure shows an IOE configured for DDR inputs for a Stratix series or APEX II device.

D Q

DFF

D Q

LATCH

ENA

D Q

DFF

INPUT

datain

inclock

neg_reg_out

dataout_l

dataout_h

Input Register A

Input Register B

Latch C

Latch

Logic

Array

Note:

On the falling edge of the clock, the negative-edge triggered register B

acquires the first data bit.

On the corresponding rising edge of the clock, the positive-edge triggered register A

acquires the

second data bit. For a successful data transfer to the logic array, the latch C

synchronizes the data

from register B

to the positive edge of the clock.

ALTDDIO Functional Description

UG-DDRMGAFCTN

2015.01.23

Altera Corporation

Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide

Send Feedback

1 2 3 4 5 6 7 8 9 10 11 ... 21 22

Kommentare zu diesen Handbüchern

Keine Kommentare

Altera Double Data Rate I/O Bedienungsanleitung Seite 6

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Messgeräte Altera Double Data Rate I/O