PEX 8632-AA Quick Start Hardware Design Guide, Version 1.1
© 2007 PLX Technology, Inc. All Rights Reserved.
13
1.7
Strapping Balls
1.7.1
Strapping Balls – 8 Port Mode
The PEX 8632 has a total of 29 Strapping balls. Sixteen service different configuration functions and
seven are STRAP_RESERVED balls. None of the Strapping balls have internal pull-up nor pull-down
resistors. If the Port configuration is fixed, use external pull-up or pull-down resistors and hardwire these
Strapping balls to the values corresponding to the Port configuration values. If a particular function is not
used, the related Configuration Strapping balls must be pulled up or down to known, disabled logic states.
(Refer to the
PEX 8632 Data Book
for details.) The STRAP_RESERVED balls have their own pull-up and
pull-down resistor requirements.
lists the names and functions of the PEX 8632 Configuration Strapping balls.
lists which
Lanes are active, depending upon whether the PEX 8632 is in 8- or 12-Port mode.
STRAP_RESERVED ball pull-up/pull-down resistor requirements.
Table 3. Configuration Strapping Balls – 8-Port Mode
Ball/Signal Name
Function
STRAP_12_PORT_MODE
Enables 12 Ports in 12-Port mode; therefore, must be tied Low in
8-Port mode.
STRAP_NT_ENABLE# Enables NT function.
STRAP_NT_UPSTRM_PORTSEL0
STRAP_NT_UPSTRM_PORTSEL1
NT Port select.
STRAP_STN0_PORTCFG0
STRAP_STN0_PORTCFG1
STRAP_STN1_PORTCFG0
STRAP_STN1_PORTCFG1
Port configuration per Station.
STRAP_TESTMODE0
STRAP_TESTMODE1
STRAP_TESTMODE2
STRAP_TESTMODE3
Test mode function select.
STRAP_UPSTRM_PORTSEL0
STRAP_UPSTRM_PORTSEL1
STRAP_UPSTRM_PORTSEL2
STRAP_UPSTRM_PORTSEL3
Upstream Port select.
