Service manual

82
8258I N/B Maintenance
8258I N/B Maintenance
5.1 Intel Yonah Processor CPU (5)
CPU Pin Description (Continued)
CPU Pin Description (Continued)
Signal Name Type Description
TCK
I TCK (Test Clock) provides the clock input for the processor Test Bus
(also known as the Test Access Port).
TDI
I TDI (Test Data In) transfers serial test data into the processor. TDI
provides the serial input needed for JTAG specification support.
TDO
O TDO (Test Data Out) transfers serial test data out of the processor.
TDO
provides the serial output needed for JTAG specification support.
TEST1,
I TEST1 must have a stuffing option of separate pull down resistor to
Vss.
TEST2
I TEST2 must have a 51±5% pull down resistor to Vss.
THERMDA
Other Thermal Diode Anode.
THERMDC
Other Thermal Diode Cathode.
THERMTRIP#
O The processor protects itself from catastrophic overheating by use of
an internal thermal sensor. This sensor is set well above the normal
operating temperature to ensure that there are no false trips. The
p
rocessor will stop all execution when the junction temperature
exceeds approximately 125°C. This is signalled to the system by the
THERMTRIP# (Thermal Trip) pin.
TMS
I TMS (Test Mode Select) is a JTAG specification support signal used
by debug tools.
TRDY#
I TRDY# (Target Ready) is asserted by the target to indicate that it is
ready to receive a write or implicit writeback data transfer. TRDY#
must connect the appropriate pins of both FSB agents.
TRST#
I TRST# (Test Reset) resets the Test Access Port (TAP) logic. TRST#
must be driven low during power on Reset.
Vcc
I Processor core power supply.
Vcca
I Vcca provides isolated power for the internal processor core PLL’s.
Vccp
I Processor I/O Power Supply.
VID[6:0]
O VID[6:0] (Voltage ID) pins are used to support automatic selection of
p
ower supply voltages (Vcc). Unlike some previous generations of
processors, these are CMOS signals that are driven by the Intel
Pentium M processor. The voltage supply for these pins must be valid
b
efore the VR can supply Vcc to the processor. Conversely, the VR
output must be disabled until the voltage supply for the VID pins
becomes valid. The VID pins are needed to support the processor
voltage specification variations. The VR must supply the voltage that
is requested by the pins, or disable itself.
Signal Name Type Description
Vsssense
O Vsssense together with Vccsense are voltage feedback signals to
IMVP6 that control the 2.1m loadline at the processor die. It should
be used to sense ground near the silicon with little noise.
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