Freescale Semiconductor MPC5553 - Nexus Signals

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 2-43
The MPC5553 has a primary signal function of CAL_ADDR[11]. The alternate signal function
FEC_MDIO provides a fast Ethernet data management I/O to manage the data output. The second alternate
signal function CAL_CS[3] provides a calibration chip select function. The FEC function FEC_MDIO and
the calibration function CAL_CS[3] are not available on the MPC5554. This pin can also be used as a
GPIO signal.
2.3.3.11 External Bus Busy / GPIO - MPC5554 Only
BB
_GPIO[74]
BB_GPIO[74] has a primary function of BB that indicates the external bus interface (EBI) is busy. The
BB_GPIO[74] signal function is not available on the MPC5553. This pin can be used as a GPIO signal for
the MPC5554 only.
2.3.4 Nexus Signals
2.3.4.1 Nexus Event In
EVTI
EVTI is an input that is read during a debug port reset to enable or disable the Nexus Auxiliary port (for
trace). After reset, the EVTI pin is used to initiate program and data trace synchronization messages or
generate a breakpoint.
2.3.4.2 Nexus Event Out
EVTO
EVTO is an output that provides timing to a development tool for a single watchpoint or breakpoint
occurrence.
2.3.4.3 Nexus Message Clock Out
MCKO
MCKO is a free running clock output to the development tools which is used for timing of the MDO and
MSEO signals.
2.3.4.4 Nexus Message Data Out
MDO[3:0]
MDO[3:0] are the trace message outputs to the development tools.
In addition to being a trace output, MDO[0] indicates the lock status of the system clock following a
power-on reset. MDO[0] is driven high following a power-on reset until the system clock achieves lock,
at which time it is then negated. There is an internal pullup on MDO[0].
2.3.4.5 Nexus Message Data Out / GPIO
MDO[11:4]_GPIO[82:75]
MDO[11:4]_GPIO[82:75] are the trace message outputs to the development tools for full port mode. These
pins function as GPIO when the Nexus port controller (NPC) operates in reduced port mode.