User`s guide

MPC8240 and MPC8260 Emulation 63
Chapter 5: Connecting and Configuring the Emulator
Designing a MPC8240 or MPC8260 Target System
Designing a MPC8240 or MPC8260 Target
System
Debug Port Connection
A 2x8 0.1 inch center BERG-style connector is required to connect the
emulation probe to the MPC8260 PowerQUICC II JTAG interface or the
MPC8240 JTAG interface. The header should be placed as close to the
microprocessor as possible to ensure signal integrity. TDO, TDI, TCK,
TMS, and TRST should have signal traces less than three inches
between the JTAG connector and the microprocessor. If these signals
are connected to other nodes, it is required that they connect in a daisy
chain between the JTAG debug connector and the MPC8260
PowerQUICC II or the MPC8240. These signals are sensitive to cross-
talk and cannot be routed next to active signals such as clocks.
The TDI, TCK, TMS, and TRST
signals must not be actively driven by
the target system when the debug port is being used.
The Agilent Technologies emulation probe/module adds about 40pF to
all target system signals routed to the debug connector. This added
capacitance may reduce the rise time of the HRESET
and SRESET
signals beyond the processor specifications. If so, the target may need
to increase the pull-up current on these signal lines.
When the 'rst' command on the probe/module is used, HRESET
is held
low for approximately 300ms.