Development Trigger Semaphore (DTS)MPC5644A Microcontroller Reference Manual, Rev. 6Freescale Semiconductor 169938.6 Example applicationThe calibration process of a new engine requires real-time access to calibration tables and the ability toupdate the tables in real-time1. The DTS module enables this capability by enabling software to assert asignal to an external device pin to notify an external tool that data is available. The tool can then retrievethe data.In this type of application the DTS_SEMAPHORE register and DTS Trigger Output (DTO) signal providea mechanism to notify the calibration tool that the calibration variable or variables (or sets ofmeasurements), up to 32, have been updated with new values and are available for the tool to access.Address: DTS_BASE+0x0008 Access: Restricted R/W11 The e200z4 core and eDMA modules can set bits in the DTS_SEMAPHORE register but cannot clear them—writesby the core and eDMA are bitwise ORed to the contents of the register. Nexus can only read this register but all bitsare cleared after the read operation.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15RST31ST30ST29ST28ST27ST26ST25ST24ST23ST22ST21ST20ST19ST18ST17ST16WRESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 016 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31RST15ST14ST13ST12ST11ST10ST9ST8ST7ST06ST5ST04ST3ST02ST1ST0WRESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0Figure 38-6. DTS_SEMAPHORE registerTable 38-5. DTS_SEMAPHORE field descriptionsName DescriptionST[31:0] Semaphore TriggerWhen a core or eDMA writes a logical ‘1’ to a bit, the bit is set. A write of ‘0’ by the core or DMA doesnot change the state of the bit.• All register bits are set to ‘1’ by a device reset.• A JTAG reset does not change the state of this register.• The register can be accessed, with restrictions, by any core, DMA or any Nexus RWA.• For the core or DMA, only 32-bit write or read accesses are valid.• A core or DMA valid read access returns the current value of the register and leaves the registerunchanged.0: No flag1: Flag is set1. MPC5644A devices also include an MMU modification feature, which enables real-time switching of calibration tables.
