Functional Description
5.27.2
Enabling integrated TPM
The integrated TPM is enabled based on the combination of a functional straps on both
the ICH and the (G)MCH and a soft strap bit found in the SPI Descriptor. When the
integrated TPM is enabled, Front Side Bus cycles that would otherwise propagate to the
LPC bus will be routed by the Config Bus Decoder to the integrated TPM Host Decoder.
Either Functional strap or the soft strap bit may be used to disable the integrated TPM.
• ICH Functional Strap: The ICH10 enables Integrated TPM when SPI_MOSI is
sampled high on the rising edge of CLPWROK and disabled if the SPI_MOSI signal is
sampled low. See Section 2.25.1 for details. The SPI_MOSI signal requires an
external pull-up resistor to enable the integrated TPM. SPI_MOSI has an integrated
pull-down resistor enabled at reset only and does not require an external pull-down
resistor to disable integrated TPM.
• Soft Strap: The integrated TPM Disable bit (bit 2) in the (G)MCHSTRP0 register
(FSMBA + 0h) within the flash descriptor can act as an override to the functional
straps on both the ICH and (G)MCH. When set, the integrated TPM will be disabled
regardless of the values of the functional straps on the ICH and/or (G)MCH. This bit
along with both functional straps must be appropriately configured to enable
integrated TPM.
• (G)MCH Functional Strap: For (G)MCH functional strap information, consult the
appropriate (G)MCH documentation.
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Datasheet
INTEL [ INTEL ]
