Intel SC5400LX User Manual

Port 8 and Port 9 of VSC7161* SAS Expander were only used as SAS host interface, each port 
connects to SAS controller of server board or HBA via a separate 7-pin SAS connector. 

The following table defines pin-out of the 7-pin SAS connector: 

1 GND 

2 SASn_EP_RX_P 

3 SASn_EP_RX_N 

4 GND 

5 SASn_EP_TX_N 

6 SASn_EP_TX_P 

7 GND 

 

The VSC7161* SAS Expander supports two independent I

2

C interface ports with bus speed of 

up to 400 Kbits. The I

2

C bus at port 0 supports a TI TMP75* or equivalent I

2

C-based 

temperature sensor. This enables actual temperature value readings to be returned to the host; 
this bus also supports an AT24C64* EEPROM or equivalent I

2

C –based EEPROM used as 

FRU. The Intelligent Platform Management Bus (IPMB) is supported through the I

2

C port 1. 

The following figure provides a block diagram of I

2

C bus connection implemented on the 4 and 6 

HDD Active SAS/SATA HSBP.  

z

Addr=0xC0 or 0xC2 

IPMB 

Addr = 0xA0 

Port 0 

Port 1 

EEPROM 

FRU 

Temp 

VSC7161 

146 & 147 

Sensor 

Addr = 0x90 

148 & 149 

LEVEL SHIFT