Altera HyperTransport MegaCore Function User Manual
Page 41
Chapter 3: Specifications
3–15
HyperTransport MegaCore Function Specification
© November 2009
Altera Corporation
HyperTransport MegaCore Function User Guide
Preliminary
The local application interface uses an Altera Atlantic interface to transfer data to the
local-side application. The local application interface has the following signal groups:
■
Rx non-posted command/data interface
■
Rx posted command/data interface
■
Rx response command/data interface
■
Tx non-posted command/data interface
■
Tx posted command/data interface
■
Tx response command/data interface
■
CSR interface
■
System signals
The following sections describe these signal groups.
f
The local application interfaces to the Rx and Tx command/data buffers using the
Altera Atlantic interface. For a detailed description of the Atlantic interface, refer to
offers an overview of the Atlantic interface information in
that is relevant for the HyperTransport MegaCore.
The Atlantic interface specification defines the
dat
signal bus to be in big-endian
format. Because HT uses little-endian format, the HyperTransport MegaCore function
uses a little-endian format across the Atlantic interface. This implementation requires
a different interpretation of the Atlantic
mty
signals, as described in the
mty
signal
descriptions in the remainder of this section.
Table 3–1. Atlantic Interface Support
Interface
Atlantic
Type
Unused
Signals
Exceptions
Rx non-posted command/data interface.
Rx posted command/data interface.
Rx response command/data interface.
Slave Source
err
par
adr
Packets are organized in the form of command
followed by data. The Dat signals hold command and
data information. When SOP is asserted, the
information driven on the Dat signal is command
information.
Side-band signals provide additional information.
Tx non-posted command/data buffer
signals
Tx posted command/data signals.
Tx response command/data signals
Slave Sink
err
par
adr
The Rjct signal indicates when the write was rejected.
This signal is a side-band signal in addition to the
Atlantic signals.
CSR signals
Not Atlantic
System signals
Not Atlantic