PLX Technology PEX 8680, Руководство по конструкции аппаратуры

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PEX 8680 Quick Start Hardware Design Guide, Version 1.1
10 © 2011 PLX Technology, Inc. All Rights Reserved.
3 Non-Transparent Function
The PEX 8680 supports Non-Transparent (NT) function. There are three ways to enable the NT function
and configure the NT Port for the PEX 8680.
Method 1. Use of the Strapping balls:

STRAP_NT_ENABLE#

STRAP_NT_UPSTREAM_PORTSEL[4:0]
Pull down the STRAP_NT_ENABLE# to logic zero (0) to enable the NT function. Pull up or down the
STRAP_NT_UPSTREAM_PORTSEL[4:0] to select the NT Port.
Method 2. Enable the NT function and configure the NT Port through the serial EEPROM. The NT
configuration settings will be loaded upon power-up and after reset.
Method 3. Use the PEX 8680 I
2
C Port 0 to enable the NT function and configure the NT Port.
Figure 10 illustrates how to implement the NT functions through the Strapping balls. Figure 11 illustrates
how to disable the NT functions, through the PEX 8680’s NT Strapping balls.
2.5V
PEX 8680
STRAP_NT_UPSTREAM_PORTSEL0
STRAP_NT_UPSTREAM_PORTSEL1
STRAP_NT_ENABLE#
2.5V
Figure 10. Enable NT Function with NT Strapping Balls
2.5V
PEX 8680
STRAP_NT_UPSTREAM_PORTSEL0
STRAP_NT_UPSTREAM_PORTSEL1
STRAP_NT_ENABLE#
Figure 11. Disable NT Function