Development Trigger Semaphore (DTS)MPC5644A Microcontroller Reference Manual, Rev. 6Freescale Semiconductor 1693Chapter 38Development Trigger Semaphore (DTS)38.1 IntroductionDevices in the MPC5644A family1 include a system development feature, the Development TriggerSemaphore (DTS) module, that enables software to signal an external tool by driving a persistent (affectedonly by reset or an external tool) signal on an external device pin. There are a variety of ways this modulecan be used, including as a component of an external real-time data acquisition system2.38.2 OverviewThe Development Trigger Semaphore (DTS) module consists of three registers and a small amount ofcombinational logic to generate an output signal—DTS Trigger Output (DTO). The registers are asfollows.• DTS_SEMAPHORE register—Any bit in this 32-bit register, when set to a value of logic ‘1’,causes the DTS module output signal to be asserted, enabling an external tool to detect up to 32signals from the application software. In an application, each bit is generally associated with aspecific data set.Only the processor core and DMA module can set bits in this register. The bits can only be clearedby a tool access via Nexus Read/Write Access over the JTAG port.• DTS_STARTUP register—This register provides a mechanism for the external tool to notifysoftware running on the CPU that the tool is connected and can provide information about eitherthe type of tool or options that can be used by the software.• DTS_ENABLE register—This register provides an enable/disable capability for the DTS feature.The architecture is shown in Figure 38-1.Figure 38-1. DTS block diagram1. Revision 2 and later2. When used as a component of a triggered data acquisition system, Nexus read/write access is via the JTAG interface of theNexus debug port and is different than the data acquisition protocol defined in the IEEE-ISTO 5001-2003 or IEEE-ISTO5001-2010 Nexus standards, which use the Nexus Auxiliary port.DTS_ENDTS_SEMPAPHORE32-bitDTS_ENABLESystem ClockSystem ResetXBAR Master IDPeripheral Bus(DTO)DTS_STARTUPDTS Trigger Output
