Debug Support
e200z3 Power Architecture Core Reference Manual, Rev. 2
Freescale Semiconductor
9-15
9.5.3
OnCE Internal Interface Signals
The following sections describe the OnCE interface signals to other internal blocks associated with the
OnCE controller.
shows the OnCE internal interface signals.
9.5.3.1
CPU Address and Attributes
The CPU address and attribute information are used by an external Nexus class 2–4 debug unit with
information for real-time address trace information.
9.5.3.2
CPU Data
The CPU data bus is used to supply an external Nexus class 2–4 debug unit with information for real-time
data trace capability.
9.5.4
OnCE Interface Signals
The following sections describe additional OnCE interface signals to other external blocks such as a Nexus
controller and external blocks that may need information pertaining to debug operation.
Table 9-4. OnCE Internal Interface Signals
Signal Name
I/O
Description
CPU Debug Request
(
dbg_dbgrq)
O
The db
g_dbgrq signal is set by the OnCE control logic to request the CPU to enter the
debug state. It may be set for a number of different conditions, and causes the CPU to finish
the current instruction being executed, save the instruction pipeline information, enter
debug mode, and wait for further commands.
CPU Debug
Acknowledge
(
cpu_dbgack)
I
The
cpu_dbgack signal is set by the CPU upon entering the debug state. This signal is used
as part of the handshake mechanism between the OnCE control logic and the rest of the
CPU. The CPU core may enter debug mode through either a software or hardware event.