System Design Information
COP_TDO
COP_TDI
NC
COP_TCK
COP_TMS
COP_SRESET
COP_HRESET
COP_CHKSTP_OUT
1
3
5
7
9
11
13
15
2
4
6
8
10
12
KEY
No pin
16
NC
COP_TRST
COP_VDD_SENSE
COP_CHKSTP_IN
NC
NC
GND
Figure 51. COP Connector Physical Pinout
17.8.1 Termination of Unused Signals
If the JTAG interface and COP header will not be used, Freescale recommends the following connections:
• 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
If this is not possible, the 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.
• Tie TCK to OV
DD
through a 10 kΩ resistor. This will prevent TCK from changing state and
reading incorrect data into the device.
• No connection is required for TDI, TMS, or TDO.
MPC8555E PowerQUICC™ III Integrated Communications Processor Hardware Specifications, Rev. 4
82
Freescale Semiconductor
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
