SMSC USB2503A - Manual (Page 37)

Integrated USB 2.0 Compatible 3-Port Hub
Datasheet
SMSC USB2503/USB2503A 37 Revision 2.3 (08-27-07)
DATASHEET
Chapter 6 XNOR Test
XNOR continuity tests all signal pins on the Hub (every pin except for NC, XTAL1/CLKIN, XTAL2,
ATEST/REG_EN, RBIAS, TEST1, Power, and Ground). This functionality is enabled by driving TEST1
and CFG_SEL[1] high, driving SCLK low and transition RESET_N from low to high. The output from
the XNOR chain is driven to GR2 . For each pin tested for continuity GR2 should toggle.