Reset, status, and link training signals – Altera Arria V GZ Avalon-ST User Manual

Page 86

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Related Information

Clocks

on page 7-5

Reset, Status, and Link Training Signals

Refer to Reset and Clocks for more information about the reset sequence and a block diagram of the reset

logic.

Table 5-6: Reset Signals

Signal

Direction

Description

npor

Input

Active low reset signal. In the Altera hardware example designs,

npor

is the

OR

of

pin_perst

and

local_rstn

coming from the

software Application Layer. If you do not drive a soft reset signal

from the Application Layer, this signal must be derived from

pin_perst

. You cannot disable this signal. Resets the entire IP

Core and transceiver. Asynchronous.
In systems that use the hard reset controller, this signal is edge,

not level sensitive; consequently, you cannot use a low value on

this signal to hold custom logic in reset. For more information

about the hard and soft reset controllers, refer to Reset.

reset_status

Output

Active high reset status signal. When asserted, this signal

indicates that the Hard IP clock is in reset. The

reset_status

signal is synchronous to the

pld_clk

clock and is deasserted only

when the

npor

is deasserted and the Hard IP for PCI Express is

not in reset (

reset_status_hip

= 0). You should use

reset_

status

to drive the reset of your application. This reset is used

for the Hard IP for PCI Express IP Core with the Avalon-ST

interface.

pin_perst

Input

Active low reset from the PCIe reset pin of the device.

pin_perst

resets the datapath and control registers. Configuration via

Protocol (CvP) requires this signal. For more information about

CvP refer to Configuration via Protocol (CvP).
Arria V GZ V devices can have up to 4 instances of the Hard IP

for PCI Express. Each instance has its own

pin_perst

signal. You

must connect the

pin_perst

of each Hard IP instance to the

corresponding

nPERST

pin of the device. These pins have the

following locations:

NPERSTL0

: bottom left Hard IP and CvP blocks

NPERSTL1

: top left Hard IP block

NPERSTR0

: bottom right Hard IP block

NPERSTR1

: top right Hard IP block

5-34

Reset, Status, and Link Training Signals

UG-01127_avst

2014.12.15

Altera Corporation

Interfaces and Signal Descriptions

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