15.5.8 DTSL MEM-AP support

DTSL provides special classes for MEM-AP support. The following figure shows the class hierarchy:

Figure 15-9 MEM-AP Class Hierarchy
MEM-AP Class Hierarchy

The figure shows two main class trees. These are the MEM-AP tree and the DeviceMemoryAccessor tree. The DTSL configuration typically creates objects for one or more of the MEM-AP class types, suitably specialized for the actual bus type.

In the MCBSTM32E example, there is an AHB-AP which can be used to access memory directly. In the case of Cortex-M3, this bus is also used to access the CoreSight debug components, but for non-Cortex-M cores it is more typical for there to be a separate APB-AP for debug component access. The significant lines of the DTSL configuration script are similar to the following:

devID = self.findDevice("CSMEMAP")
self.AHB = CortexM_AHBAP(self, devID, "CSMEMAP")		

In this case, the RDDI-DEBUG configuration has a device called CSMEMAP, which associates with a CortexM_AHBAP DTSL object. This object is derived from a DTSL Device, and so has memory access methods available.

If a client is aware of such DTSL devices, then it can use them to access memory directly.

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