24
All signal names and clock pin positions are located in
Table 4-3 XAUI to SFP+ HSMC Board Clock Distribution
Frequency Signal Name
Signal
Originates
From
Signal Propagates To
156.25
MHz
HSM_CLK_P
HSM_CLK_N
U16.13
U16.14
156.25
MHz
PEXTCLK156_P
PEXTCLK156_N
U16.17
U16.18
J16.156
J16.158
U6.T10
U6.R10
156.25
MHz
CLK0_P
CLK0_N
U16.21
U16.22
J7
J8
4.4
4.4
Memory
Devices
Memory Devices
This section describes the board’s memory interface support, and their signal names, types, and
connectivity relative to the interface they are connected to. The board has the following memory
interfaces:
8K EEPROM (connected to HSMC)
2 x 256K SPI EEPROM (connected to BCM8727 and HSMC)
2 x 4K EEPROM (connected to BCM8727 and SFP+)
The 8K EEPROM intended use is to identify the board when it is plugged into the host board.
All signal names and memory pin positions are located in Table 4-4, Table 4-5, and Table 4-6.
Table 4-4 8 Kbit Serial I2C EEPROM (24LC08B) Pinout
Board
Reference
Signal Name
IO Standard
Function
U18.1
GND
GND
Address bus bit 0
U18.2
GND
GND
Address bus bit 1
U18.3
GND
GND
Address bus bit 2
U18.4
GND
GND
Ground
U18.5
SMB_SDA
3.3V
Serial Data
U18.6
SMB_SCL
3.3V
Serial Clock
U18.7
GND
GND
Write Protect
U18.8
VCC
3.3V
3.3V Power Supply
