PPC8567ECVTANJGA datasheet(134/139 Pages) FREESCALE

134 / 139 page

MPC8568E/MPC8567E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 1

134

Freescale Semiconductor

System Design Information

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, then the COP reset signals must be

merged into these signals with logic.

The arrangement shown in Figure 75 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.

The COP header shown in Figure 75 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 75; 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 75 is common to all known emulators.

PPC8567ECVTANJGA 数据表(PDF) 134 Page - Freescale Semiconductor, Inc