82801CA Datasheet, PDF (54/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

Signal Description
Figure 2-3. Example V5REF Sequencing Circuit
Vcc Supply
(3.3 V)
5 V Supply
1 KΩ
1 µF
To System
5VREF
To System
2.20.4 Test Signals
2.20.4.1
Test Mode Selection
When PWROK is active (high) for at least 76 PCI clocks, driving RTCRST# active (low) for a
number of PCI clocks (33 MHz) will activate a particular test mode a specified in Table 2-21.
Note: RTCRST# may be driven low any time after PCIRST is inactive. Refer to Section 18.1, “Test Mode
Description” on page 18-487 for a detailed description of the ICH3-S test modes.
Table 2-21. Test Mode Selection
Number of PCI Clocks RTCRST# driven low after
PWROK active
<4
4
5
6
7
8
9–42
>42
Test Mode
No Test Mode Selected
XOR Chain 1
XOR Chain 2
XOR Chain 3
XOR Chain 4
All “Z” (Tri-state Mode)
Reserved. DO NOT ATTEMPT
No Test Mode Selected
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Intel^® 82801CA ICH3-S Datasheet