Pex 8608 Strapping Balls; Table 3. Strapping Balls - PLX Technology PEX 8608 Quick Start Manual

9

PEX 8608 Strapping Balls

The PEX 8608 has a total of 22 Strapping balls. Eleven of them service different configuration functions. For the
PEX 8608, none of the Strapping balls, including the Strapping balls for configuration, have internal pull-up or 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 desired. If a particular function is not used,
the related Strapping ball must pull up or pull-down to a known disabled logic state.
functions of the PEX 8608 Strapping balls.
Ball/Signal Name
STRAP_SERDES_MODE_EN#
STRAP_PROBE_MODE#
STRAP_DEBUG_SEL0
STRAP_FAST_BRINGUP#
STRAP_RESERVED16
STRAP_RESERVED17#
STRAP_PLL_BYPASS#
STRAP_SSC_ISO_ENABLE#
STRAP_NT_ENABLE#
STRAP_NT_P2P_EN#
STRAP_NT_UPSTRM_PORTSEL0
STRAP_NT_UPSTRM_PORTSEL1
STRAP_NT_UPSTRM_PORTSEL2
STRAP_NT_UPSTRM_PORTSEL3
STRAP_PORTCFG0
STRAP_PORTCFG1
STRAP_TESTMODE0
STRAP_TESTMODE1
STRAP_TESTMODE2
STRAP_TESTMODE3
STRAP_UPSTRM_PORTSEL0
STRAP_UPSTRM_PORTSEL1
STRAP_UPSTRM_PORTSEL2
STRAP_UPSTRM_PORTSEL3
STRAP_SPARE0#
STRAP_SPARE1#
STRAP_SMBUS_EN#
PEX
8608 Quick Start Hardware Design Guide – Version 1.2
Copyright © 2009 by PLX Technology, Inc. All rights reserved.

Table 3. Strapping Balls

Enable SerDes Mode Debug Function
Enable Probe Mode Debug Function
Factory Test. Tied High.
Factory Test. Tied High.
Factory Test. Tied Low.
Factory Test. Tied High.
Factory Test. Tied High.
Enable RefClk Isolation function.
Enable NT function
Enable NT function to be placed logically on the internal virtual PCI Bus or behind the
Peer-to-Peer bridge
NT Port select
Port configuration.
Test mode function select.
Upstream Port select.
Factory Test. Do not connect.
Factory Test. Tied High.
Enable SMBus interface.
Table 3 lists the names and
Functions
17