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AURIX™ MCU: Access priority to Extension Memory (EMEM) – KBA237963

AURIX™ MCU: Access priority to Extension Memory (EMEM) – KBA237963

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Community Translated: AURIX™ MCU:拡張メモリ(EMEM)へのアクセス優先度 – KBA237963

Question: How can I use the priority mechanism to access the Extension Memory (EMEM) for my application and for tracing?


The Extension Memory (EMEM) is used for multiple use cases, such as application (Autonomous Driving – ADAS), calibration, or trace data storage. EMEM is organized in RAM blocks called tiles. Each block has four interfaces to communicate with the outside modules:

  • MCDS: used for moving traced data from the traced sources to EMEM
  • SEP: used by the Signal Processing Unit (SPU) in application mode
  • SRI: used for application mode
  • BBB: used for tool mode, where tools can access the data in EMEM

The EMEM tiles can be switched between different modes; therefore, multiple accesses can be made to one tile. To avoid conflicts, a prioritization mechanism is enabled. The accesses made by SPU via SEP get the highest priority. Second, SRI accesses are prioritized, followed by BBB accesses.

The MCDS interface is not part of the prioritization mechanism since it works independently from the other interfaces.

If the EMEM tiles are misconfigured or there are any concurrent accesses, the debugger may appear to stall while waiting for access via the BBB.


Figure 1 Extension Memory

Note: This KBA applies to the following series of AURIX™ MCUs.

  • AURIX™ TC2xx series
  • AURIX™ TC3xx series