Altera HyperTransport MegaCore Function - 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
FS
13: Atlantic Interface .
Table 3–1 offers an overview of the Atlantic interface information in FS 13: Atlantic
Interface 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