Data Sheet
PowerPC® 750CXr RISC Microprocessor
Preliminary
Figure 6-3. IBM RISCWatch JTAG to HRESET, TRST, and SRESET Signal Connector
HRESET from RISCWatch
HRESET to 750CX
System HRESET
TRST to 750CX
TRST from RISCWatch
SRESET from RISCWatch
SRESET to 750CX
System SRESET
Note: See notes for Table 6-3 on page 38.
6.6 Thermal Management Information
This section provides thermal management information for the PBGA package for air cooled applications.
Proper thermal control design is primarily dependent upon the system-level design and air flow.
6.6.1 Thermal Assist Unit
The thermal sensor in the Thermal Assist Unit (TAU) has not been characterized to determine the basic
uncalibrated accuracy. The relationship between the actual junction temperature and the temperature
indicated by THRM1 and THRM2 is not well known.
IBM recommends calibration of the TAU in these devices before use. Calibration methods are discussed in
the IBM Application Note Calibrating the Thermal Assist Unit in the IBM25PPC750L Processors. Although
this note was written for the 750L, the calibration methods discussed in this document also apply to the
750CXr.
6.6.2 Heat Sink Considerations
The PowerPC 750CXr package will support a maximum normal load of 2.2kg. This load includes the heat
sink and any forces used to position or fasten the heat sink.
System Design Information
Page 40 of 43
750cxr_DD4.0_Dev_gen_4_mkt.fm
February 28, 2005
IBM [ IBM ]
