Artesyn RTM ATCA-F140 Installation and Use (July 2014) - Manual (Page 47)

Functional Description
RTM-ATCA-F140 Installation and Use (6806800M97F) 47
4.6.6.1 QSFP+ I2C Bus
The QSFP+ I2C bus signals (I2C_SDA and I2C_SCL) from each SFP+ site are individually
connected to the BCM84740 which includes a mechanism to allow access to the port through
the PHY management channel.
4.6.6.2 QSFP+ Status Signals
The QSFP+ status signals, MODPRS#, and INT#, are individually connected to the BCM84740
which monitors them. The signals are also connected to the RTM FPGA to allow fast detection
of a loss of signal condition. Refer to
Chapter 4, GPS Connectors, on page 48 for further details.
4.6.6.3 QSFP+ Control Signals
The QSFP+ LPMODE signal is connected to the BCM84740. This allows software control of the
power mode, or hardware control through deassertion of the TXONOFF signal.
4.6.7 PHY Management Interfaces
The BCM84740 provides a single MDC/MDIO management port to access all four channels and
allows bits 0 and 1 of the PHY address for each channel to be individually programmed, with
bits 2 - 4 being common.
Table 4-10"BCM84740 PHY Addressing" shows the address allocation
and management port definition for each channel.
17 RX1+ 22 RX2+
18 RX1- 21 RX2-
19 GND 20 GND
Table 4-9 QSFP+ Connector Pin Assignment (continued)
Pin Signal Pin Signal
Table 4-10 BCM84740 PHY Addressing
PHY
Address
High Bits
Channel Source
PHY
Address
Low Bits
PHY
Address
Switch Port
QSFP+
Port Management
Channel
b000 0 Fabric b00 0 FIX_P14
Lane 0 Fabric
QSFP+ FIX_XG_MDC
2/ MDIO2