Input/output avalon-mm master, Input/output avalon-mm master –81 – Altera RapidIO II MegaCore Function User Manual

Page 123

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Chapter 4: Functional Description

4–81

Error Detection and Management

August 2014

Altera Corporation

RapidIO II MegaCore Function

User Guide

■

Illegal Transaction Decode

is declared for malformed received response packets

occurring from any of the following events:

■

NREAD

or NWRITE_R response packet with status not DONE nor ERROR.

■

NWRITE_R

response packet with payload or with a transaction type indicating

the presence of a payload.

■

NREAD

response packet without payload, with incorrect payload size, or with a

transaction type indicating absence of payload.

Registers in the Implementation Defined Space

The I/O Avalon-MM slave module defines the Input/Output Slave Interrupt
registers with the following bits. For details on when these bits are set, refer to their
descriptions in

Table 6–60 on page 6–40

.

■

INVALID_READ_BURSTCOUNT

■

INVALID_READ_BYTEENABLE

■

INVALID_WRITE_BYTEENABLE

■

INVALID_WRITE_BURSTCOUNT

■

WRITE_OUT_OF_BOUNDS

■

READ_OUT_OF_BOUNDS

When any of these bits are set, the system interrupt signal io_s_mnt_irq is also
asserted if the corresponding bit in the Input/Output Slave Interrupt Enable
register (

Table 6–61 on page 6–41

) is set.

The Avalon-MM Slave Interface's Error Indication Signal

The ios_rd_wr_readresponse output is asserted when a response with ERROR status is
received for an NREAD request packet, when an NREAD request times out, or when the
Avalon-MM address falls outside of the enabled address mapping window. As
required by the Avalon-MM interface specification, a burst in which the
ios_rd_wr_readresponse

signal is asserted completes despite the error signal

assertion.

Input/Output Avalon-MM Master

The I/O Avalon-MM master module processes the request packets that it receives and
generates response packets when required. Anomalies are reported through one or
both of the following two channels:

■

Standard error management registers

■

Response packets with ERROR status

Standard Error Management Registers

The following two standard defined error types can be declared by the
I/O Avalon-MM master module. The corresponding bits are then set and the required
packet information is captured in the appropriate error management registers.

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