NexusMPC5566 Microcontroller Reference Manual, Rev. 2Freescale Semiconductor 25-51NOTEWhen DC[PTM] is set, direct branch messages are not transmitted. Instead,each direct branch or predicated instruction toggles a bit in the historybuffer.25.13.2.4 Resource Full MessagesThe resource full message is used in conjunction with the branch history messages. The resource fullmessage is generated when the internal branch/predicate history buffer is full, or if the BTM Instructionsequence counter (I-CNT) overflows. If synchronization is needed at the time this message is generated,the synchronization is delayed until the next branch trace message that is not a resource full message.The current value of the history buffer is transmitted as part of the resource full message. This informationcan be concatenated by the tool with the branch/predicate history information from subsequent messagesto obtain the complete branch history for a message. The internal history value is reset by this message,and the I-CNT value is reset as a result of a bit being added to the history buffer.Figure 25-32. Resource Full Message Format25.13.2.5 Debug Status MessagesNOTEDebug Status Messages (DSMs) are enabled if the Nexus module is enabled.Debug status messages report low power mode and debug status. Entering/exiting debug mode as well asentering a low power mode triggers a debug status message.Debug status information is sent out in the following format:Figure 25-33. Debug Status Message FormatTCODE (011011)RCODE(6 bits)(4 bits)Src. Proc.(4 bits)Max length = 46 bits; Min length = 15 bits(1–32 bits)RDATASTATUS [31:24]MSB LSB12SRC TCODE (000000)36 bits4 bits8 bitsFixed length = 18 bits
