For the standard configuration where the size of the MTB is ≤ 25% of the total RAMcapacity, it is recommended the MTB be based at the address defined by the MTB_BASEregister. The read-only MTB_BASE register is defined by the expression (0x2000_0000 -(RAM_Size/4)). For this configuration, the MTB_POSITION register is initialized to(MTB_BASE & 0x0000_7FF8).If the size of the MTB is more than 25% but less than or equal to 50% of the total RAMcapacity, it is recommended the MTB be based at address 0x2000_0000. In thisconfiguration, the MTB_POSITION register is initialized to (0x2000_0000 &0x0000_7FF8) = 0x0000_00000.Following these two suggested placements provides a full-featured circular memorybuffer containing program trace packets.In the unlikely event an even larger trace buffer is required, a write-once capacity of 75%of the total RAM capacity can be based at address 0x2000_0000. The MTB_POSITIONregister is initialized to (0x2000_0000 & 0x0000_7FF8) = 0x0000_0000. However, thisconfiguration cannot support operation as a circular queue and instead requires the use ofthe MTB_FLOW[WATERMARK] capability to automatically disable tracing or haltingthe processor as the number of packet writes approach the buffer capacity. See theMTB_FLOW register description for more details.Address: F000_0000h base + 0h offset = F000_0000hBit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16RPOINTERWReset x* x* x* x* x* x* x* x* x* x* x* x* x* x* x* x*Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0RPOINTERWRAP 0WReset x* x* x* x* x* x* x* x* x* x* x* x* x* x* 0 0* Notes:x = Undefined at reset.•MTB_POSITION field descriptionsField Description31–3POINTERTrace Packet Address Pointer[28:0]Trace packet address pointer. Because a packet consists of two words, the POINTER field is the addressof the first word of a packet. This field contains bits[31:3] of the RAM address where the next trace packetis written. Therefore, it points to an unused location and is automatically incremented.Table continues on the next page...Memory Map and Register DefinitionKL04 Sub-Family Reference Manual, Rev. 3.1, November 2012274 Freescale Semiconductor, Inc.
