Development Trigger Semaphore (DTS)MPC5644A Microcontroller Reference Manual, Rev. 61694 Freescale SemiconductorThe DTS Trigger Output (DTO) signal is connected to one of the EVTO inputs of the Nexus PortController (NPC). The other EVTO inputs to the NPC are connected to the other Nexus modules in thedevice. DTO is asserted when any bit in the DTS_SEMAPHORE register is set.NOTEWhen the DTS module is enabled (DTS_ENABLE[DTS_EN] = 0b1), theNexus EVTO function of the EVTO pin is disabled and EVTO becomes theDTO. Unlike the EVTO function that only asserts for one clock, the DTOfunction remains asserted until the tool reads the DTS_SEMAPHOREregister, clearing the register’s contents.Figure 38-2 shows the chain of events that begins with setting of any bit in the DTS_SEMAPHOREregister and the clearing of the register caused by a Nexus read.Figure 38-2. DTO event sequence38.3 DTS device connectionsThe DTS module connects to the Peripheral Bridge (PBRIDGE) for access to the registers. The PBRIDGEis connected to a slave port of the Crossbar bus interface (XBAR). Connected to the XBAR master portsare the core (e200z4, with one master port for the Instruction and another for the Load/Store bus), theeDMA module, the FlexRay module, and an External Bus interface 1.The registers have limited access as described in Section 38.3.1, DTS register access. Access is based onthe XBAR Master ID of the accessing module. Access to the DTS_SEMAPHORE register is limited to thee200z4 core and the eDMA module and is restricted to only setting bits. Only an access via a NexusRead/Write Access from an external tool through the Nexus/JTAG port of the device can clear bits in the1. The External Bus Interface XBAR master port is used for internal test of the device and is not accessible to the user.DTS Trigger Output (DTO)EVTO pinDTS_SEMAPHORE registerCPU writesDTS_SEMAPHOREto a non-zero valueInternal DTO signalis assertedEVTO assertedexternallyInitial conditions:– DTS_ENABLE[DTS_EN] = 0b1– DTS_SEMAPHORE = 0x0000_0000Nexus RWA readsDTS_SEMAPHORE,which clears registerInternal DTOsignal is negatedEVTO negatedexternally~~~~~~
