mpc8240ed Freescale Semiconductor, Inc, mpc8240ed Datasheet - Page 38

• Manufacturer Part Number: mpc8240ed
• Description: Integrated Processor
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor, Inc.
System Design Information
System Design Information
interface connects primarily through the JTAG port of the processor, with some additional status monitoring
signals. The COP port requires the ability to independently assert HRESET or TRST in order to fully control
the processor. If the target system has independent reset sources, such as voltage monitors, watchdog timers,
power supply failures, or push-button switches, the COP reset signals must be merged into these signals with
logic.
The arrangement shown in Figure 25 allows the COP to independently assert HRESET or TRST, while
ensuring that the target can drive HRESET as well. If the JTAG interface and COP header will not be used,
TRST should be tied to HRESET so that it is asserted when the system reset signal (HRESET) is asserted
ensuring that the JTAG scan chain is initialized during power-on.
The COP header shown in Figure 25 adds many benefits—breakpoints, watchpoints, register and memory
examination/modification, and other standard debugger features are possible through this interface—and
can be as inexpensive as an unpopulated footprint for a header to be added when needed.
The COP interface has a standard header for connection to the target system, based on the 0.025"
square-post, 0.100" centered header assembly (often called a Berg header).
There is no standardized way to number the COP header shown in Figure 25; consequently, many different
pin numbers have been observed from emulator vendors. Some are numbered top-to-bottom then
left-to-right, while others use left-to-right then top-to-bottom, while still others number the pins counter
clockwise from pin 1 (as with an IC). Regardless of the numbering, the signal placement recommended in
Figure 25 is common to all known emulators.
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MPC8240 Integrated Processor Hardware Specifications
MOTOROLA
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