MPC8536-RDK Freescale Semiconductor, MPC8536-RDK Datasheet - Page 118

• Manufacturer Part Number: MPC8536-RDK
• Description: BOARD REF COMEXPRESS MPC8536
• Manufacturer: Freescale Semiconductor
• Series: PowerQUICC ™r
• Type: MPUr

Specifications of MPC8536-RDK

• Contents: CSB1880, CSB1801, Cables, Documentation, Enclosure, Power Supply with cord
• For Use With/related Products: MPC8536
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

JTAG Configuration Signals
level puts the device into the default state and external resistors are needed only when non-default settings are required by the
user.
Careful board layout with stubless connections to these pull-down resistors coupled with the large value of the pull-down
resistor should minimize the disruption of signal quality or speed for output pins thus configured.
The platform PLL ratio and e500 PLL ratio configuration pins are not equipped with these default pull-up devices.
3.10
Correct operation of the JTAG interface requires configuration of a group of system control pins as demonstrated in
Care must be taken to ensure that these pins are maintained at a valid deasserted state under normal operating conditions as most
have asynchronous behavior and spurious assertion will give unpredicatable results.
Boundary-scan testing is enabled through the JTAG interface signals. The TRST signal is optional in the IEEE 1149.1
specification, but it is provided on all processors built on Power Architecture technology. The device requires TRST to be
asserted during power-on reset flow to ensure that the JTAG boundary logic does not interfere with normal chip operation.
While the TAP controller can be forced to the reset state using only the TCK and TMS signals, generally systems assert TRST
during the power-on reset flow. Simply tying TRST to HRESET is not practical because the JTAG interface is also used for
accessing the common on-chip processor (COP), which implements the debug interface to the chip.
The COP function of these processors allow a remote computer system (typically, a PC with dedicated hardware and debugging
software) to access and control the internal operations of the processor. The COP 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, then the COP reset signals must be merged into
these signals with logic.
The arrangement shown in
target can drive HRESET as well.
The COP interface has a standard header, shown in
square-post, 0.100" centered header assembly (often called a Berg header). The connector typically has pin 14 removed as a
connector key.
The COP header adds many benefits such as breakpoints, watchpoints, register and memory examination/modification, and
other standard debugger features. An inexpensive option can be to leave the COP header unpopulated until needed.
There is no standardized way to number the COP header; 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
3.10.1
If the JTAG interface and COP header will not be used, Freescale recommends the following connections:
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TRST should be tied to HRESET through a 0 kΩ isolation resistor so that it is asserted when the system reset signal
(HRESET) is asserted, ensuring that the JTAG scan chain is initialized during the power-on reset flow. Freescale
recommends that the COP header be designed into the system as shown in
isolation resistor will allow future access to TRST in case a JTAG interface may need to be wired onto the system in
future debug situations.
No pull-up/pull-down is required for TDI, TMS, or TDO.
JTAG Configuration Signals
Termination of Unused Signals
Figure 79
MPC8536E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 3
Figure 78
is common to all known emulators.
allows the COP port to independently assert HRESET or TRST, while ensuring that the
Figure
79, for connection to the target system, and is based on the 0.025"
Figure
78. If this is not possible, the
Freescale Semiconductor
Figure
78.