Table of Contents
Advertisement
SIGNALS REFERENCE
A.1.47. TCK (I)
The TCK (Test Clock) signal provides the clock input for the Pentium II processor Test Bus
(also known as the Test Access Port).
A.1.48. TDI (I)
The TDI (Test Data In) signal transfers serial test data into the Pentium II processor. TDI
provides the serial input needed for JTAG specification support.
A.1.49. TDO (O)
The TDO (Test Data Out) signal transfers serial test data out of the Pentium II processor.
TDO provides the serial output needed for JTAG specification support.
A.1.50. TESTHI (I)
The TESTHI signal must be connected to a 2.5V power source through a 1 –10 kΩ resistor
for proper processor operation.
A.1.51. 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 processor will stop all execution when the junction temperature exceeds
approximately 130°C. This is signaled to the system by the THERMTRIP# (Thermal Trip)
pin. Once activated, the signal remains latched, and the processor stopped, until RESET#
goes active. There is no hysteresis built into the thermal sensor itself; as long as the die
temperature drops below the trip level, a RESET# pulse will reset the processor and
execution will continue. If the temperature has not dropped below the trip level, the
processor will continue to drive THERMTRIP# and remain stopped.
A.1.52. TMS (I)
The TMS (Test Mode Select) signal is a JTAG specification support signal used by debug
tools.
A-14
Advertisement
Table of Contents
