Intel Model Vehicle MPRTM0020 User Manual

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+1.8V: The 1.8 V voltage is used as the input voltage to the SAS re-driver IC.

The MPCBL0020 Single Board Computer implements optional SAS storage access via the 
MPRTM0020 RTM. SAS is a 3-Gbps SERDES style bus, and a redriver is added on the RTM to 
effectively detect and correct the SAS OOB signals at a proper amplitude. 

The specific SAS re-driver that was used is the PMC-Sierra* PM8380 Quad SMX 3G SATA/SAS 
Mux/Demux. The RTM implements the PM8380 device as a 1:1 re-driver. The four host ports are 
connected to the SBC via the Zone 3 connector. 

The four SAS ports of the “B” Load-side Mux-port are connected to the External SAS connector. 
The “A” Load-side Mux-port is left unconnected. The PM8380 has its configuration straps set to 
operate in re-driving mode, rather than in Mux mode. The “B” Load-side Mux-port is configured 
for the default SAS amplitude, pre-emphasis, and equalization. 

 illustrates the SAS port distribution on the RTM.

Only three SAS ports are routed to the MPRRTM0020 RTM because the first SAS port from the 
SAS HBA (port 0) is used for the on-board SAS hard drive on the MPCBL0020 SBC.

The Hot Swap, Out of Service, and Health LEDs on the RTM faceplate are fronted by the 
MPCBL0020 Single Board Computer. These LEDs have identical state to the LEDs on the SBC 
faceplate and allow service personnel to verify the state of the board when servicing the board from 
the rear of the chassis.

SAS HDD

0
1
2
3

0
1
2
3

0

Host

 

Port

A-Port (Not 

Connected)

0
1
2
3

B-Por

t

S

AS Connec

to

r

External cable
to a SAS JBOD

J31P31