Support ETM tracing for MMC [CPU.SchDoc]
The LPC1768 has support for the Embedded Trace Macrocell (ETM). This interface allows tracing the full execution flow in real time and reconstruct the flow that lead to an anomalous condition. It would be very useful when debugging the MMC firmware as stopping the MCU is not an option in a lot of cases.
The trace data can be sampled from the TRACEDATA[0-3] and TRACECLK pins (P2[2], P2[3], P2[4], P2[5] and P2[6]).
My suggestion is moving the signals FMC2_JTAG_Override
, I2C_MUX_ADDR1
, I2C_MUX_ADDR2
, LATCH1
and LATCH2
to pins P0[4] - P0[8] to free the trace pins.
I'm aware there is an ongoing effort to reduce the total number of connectors for the AFC4 and if adding a 6 pin connector is not an option now I would be satisfied with those signals routed to exposed pads (pogo pins style).