307013-003 Datasheet, PDF (839/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

Testability (Desktop and Mobile Only)
25 Testability (Desktop and Mobile
Only)
The ICH7 supports XOR Chain test mode. This non-functional test mode is a dedicated
test mode when the chip is not operating in its normal manner. The XOR Chain Mode is
entered as indicated in Figure 25-1.
Figure 25-1. XOR Chain Test Mode Selection, Entry and Testing
XOR Chain Test Mode Selection, Entry and Testing
PCICLK
RSMRST#/
LAN_RST#
5ms 10ms
Run 120 ms Run 2 ms
RTCRST#
PWROK
REQ[4:1]#
ACZ_SDOUT/
EE_DOUT
Chain Select (1-5)
TP3 / GPIO25
DMI_CLK
HeldLow
DMI_CLKp = ‘0’
DMI_CLKn = ‘1’
Toggle
XOR Output Enabled
Notes: RSMRST#, PWROK, RTCRST#, LAN_RST# must be held high during test mode and output testing.
PCICLK & DMI_CLK should be approximately 1 MHzwhile running/toggling
For chains 4 and 5, all PETx[n] signals (of that chain) must be driv en during testing.
REQ# Settings
REQ[4:1]# = 0000
REQ[4:1]# = 0001
REQ[4:1]# = 0010
REQ[4:1]# = 0011
REQ[4:1]# = 0100
REQ[4:1]# = 0111
XOR Chain
XOR 1
XOR 2
XOR 3
XOR 4
XOR 5
ALL-Z
Intel ^® ICH7 Family Datasheet
839