Ports - IBM 3534-F08 Installation And User Manual

transferred in a single operation. Additionally, because there are two buffers
available, the firmware can perform a read or write on a frame in one of the buffers
while the ASIC streams another frame into the other buffer.
ASIC
The ASIC provides eight Fibre Channel ports that you can use to connect to
external node ports (N_ports) (as an F_port) or external loop devices (as an
FL_port). You can connect one port (as an E_port) to another 3534 or 2109 series
switch. With the fabric upgrade, you might have up to eight E_ports.
Each port can operate at either 1.0625 Gbps or 2.125 Gbps link speeds. The ASIC
contains the Fibre Channel interface logic, message and buffer queuing logic,
receive buffer memory for the eight on-chip ports, and other support logic.
The Bloom ASIC is a PCI slave to the CPU. The ASIC interfaces through an
inter-chip 10-bit SSLT2 bus connection clocked at 106.25 MHz. An 8-channel
SERDES is used to support eight ports. The interface between ASIC and SERDES
is also a 10-bit SSTL2 bus running at 106.25 MHz. The SERDES converts the
10-bit wide parallel data from the SSTL2 bus into high-speed serial data for the
SFP media and vice versa. The SERDES supports single data rate (SDR) or double
data rate (DDR) transfer between the SERDES and the SFP media. Implementing
the SERDES external to the ASIC reduces the risk of silicon packaging as well as
the risk of running 2.125 Gbps signals on a board with a long trace length.
The SFP media interfaces with external devices and enables support for shortwave
laser and longwave laser. Two LEDs for each port provide port status and link
speed information.
Control Message Interface: The 3534 Model F08 Control Message Interface
(CMI) consists of a set of control signals that are used to pass hardware-level
messages between ports. Recipient ports use these control signals to inform
transmitting ports when a new frame needs to be added to the output queue of the
transmitter. Transmitting ports also use the CMI to inform recipient ports that a
frame transmission has been completed. A recipient port is free to reuse a receive
buffer when it receives notification that the frame has been transmitted. In the case
of multicast, multiple notifications are required to determine when a receive buffer is
freed.
The CMI interface for the ASIC is connected inside the ASIC. Each chip time slices
its output port to each possible destination chip in the switch. If it has a message to
send to a particular destination during the corresponding time slot, the chip uses the
time slot to send the message. Otherwise, the output port lines are driven to
indicate that no message is present.

Ports

The 3534 Model F08 supports the following port types:
v Optical ports
v Ethernet port
v Serial port
The ASIC in the 3534 Model F08 connects up to eight SFP modules. SFP devices
are encased in metal to ensure low emissions and high thermal management. They
are hot-swabble and use industry-standard local channel connectors. Each port
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IBM TotalStorage SAN Switch: 3534 Model F08 Installation and User's Guide