Intel Pentium III Processor/840, Manual, Page: 37 / 151

Intel
®
Pentium
®
III Processor/840 Development Kit Manual 4-1
Hardware Reference
4
This section provides reference information on the system hardware, including connector pinout
information and jumper settings.
4.1 Thermal Management
The objective of thermal management is to ensure that the temperature of each component is
maintained within specified functional limits. The functional temperature limit is the range within
which the electrical circuits can be expected to meet their specified performance requirements.
Operation outside the functional limit can degrade system performance and cause reliability
problems.
The Intel
®
Pentium
®
III
processor/840 Development Kit is shipped with two heatsink/fan thermal
solutions pre-installed on the primary and secondary processors using metallic clips. These thermal
solutions have been tested in an open air environment at room temperature and are sufficient for
evaluation purposes. The designer must ensure that adequate thermal management is provided for
any customer-derived designs.
4.2 In-Target Probe (ITP) Debugger Port
The evaluation platform is populated with a 1.5-V In-Target Probe (ITP) debugger port. The ITP
port provides a path for debugger tools like emulators, in-target probes, and logic analyzers to gain
access to the processor’s registers and signals without affecting high speed operation. This allows
the system to operate at full speed with the debugger attached.
Caution: The ITP connector used on this board requires a 1.5-V supply voltage.
4.3 Post Code Display
The evaluation board has an on-board Post Code Display. Data from any code that does an I/O
write to 80H is latched on the two LED displays (U10C1 upper nibble/U11C1 lower nibble).
During BIOS startup, code is posted to these LEDs to indicate what the BIOS is doing. Application
code can post its own data to these LEDs by performing an I/O write to address 80H. The Altera
EPM7064S PLD code used to implement this function is included in Appendix C, “PLD Code
Listing.”
4.4 WTX Power Supply
WTX is a new form factor developed for the mid-range workstation market. The WTX
specification goes beyond standard form factor specifications to specify the size and shape of the
board and the interface between the board and chassis.
For more information on the WTX form factor, go to www.WTX.org.