ADVANCE
INFORMATION
CYL2T0201
The MetroLink2T-2 mapping engine follows the ITU recom-
mendation G.7041 from January 2002. The GFP-T engine in
the MetroLink2T-2 device supports one or two channels, and
contains protocol-specific functions to allow the seamless
transport of Fibre Channel, FICON, ESCON, or GbE.
Overview
Applications
Metro service aggregation nodes aggregate client traffic such
as GbE, ESCON, or Fibre Channel into SONET/SDH payloads
for long-haul transport. Such nodes require the ability to
ensure just the right amount of bandwidth is allocated for the
client payload -- which is where virtual concatenation becomes
beneficial due to its convenience in specifying payload size.
SPI-3 Interface
The SPI-3 interface was designed to support Packet-over-
SONET/SDH (POS) in the OC-48/STM-16 (2.488 Gbps) and
below environment. It allows efficient packet transfer between
a framer and a link layer device. SPI-3 supports multiple ports
and has in-band port selection.
The MetroLink2T-2 Link-Layer device aggregates two
channels of GbE, Fibre Channel, FICON, or ESCON client
traffic onto a single SPI-3 bus. The MetroLink2T-2 SPI-3
interface connects to the POSIC2GVC/POSIC2G framer
which is used to create the SONET/SDH frame required for
network transport.
SPI-3 has discrete transmit/receive control signals for Start of
Packet (SOP), End of Packet (EOP), start of transfer, error
indications, and other control indications. Transmit FIFO
status flow control is provided by using either a polling or a
direct status indication scheme.
SERDES Interface
The CYL2T0201 MetroLink2T-2 GFP-T mapper interface to
the two-channel SERDES device supports the following
functions:
Since the SPI-3 interface supports data transfers at clock rates
independent of the actual line bit rate, FIFOs are specified to
allow the rate decoupling.
• Error detection and handling
• Egress rate adaptation.
The SPI-3 interface specifies parity on the data bus. SPI-3 also
specifies a maximum clock rate of 104 MHz.
The SERDES interface allows for a seamless connection to
the CY15G0201DX device, as shown in Figure 1.
Since the SPI-3 interface is a point-to-point interface, the
MetroLink2T-2 should connect to one framer device, such as
a POSIC2GVC. SPI-3 and MetroLink2T-2 support variable-
length packets. MetroLink2T-2 supports the 32-bit-wide
packet-level transfer mode of SPI-3.
GFP-T Engine
GFP-T is a version of GFP that provides the benefits of frame-
mapped GFP (header error correction/rugged links,” known
transport bandwidth/no byte-stuffing) with low latency.
In SPI-3, the PHY port address is inserted in-band with the
packet data being transferred on the data bus. SPI-3 allows up
to 256 ports; since MetroLink2T-2 is a two-channel device,
only one or two SPI-3 ports are supported by MetroLink2T-2.
ESCON is a registered trademark, and FICON is a trademark, of IBM Corporation. MetroLink2T-2, POSIC2GVC, and POSIC2G
are trademarks of Cypress Semiconductor. All product and company names mentioned in this document are the trademarks of
their respective holders.
Document #: 38-02071 Rev. **
Page 3 of 4
© Cypress Semiconductor Corporation, 2003. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
