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On-chip XRAM

Some C16x/XC16x derivatives have additional on-chip XRAM. This memory is physically located on-chip but is accessed using the external data bus. This memory is subject to the same limitations as external memory (including timing).

You may declare XRAM variables using the sdata memory type. You may also use sdata pointers to access XRAM memory.


  • Access to on-chip XRAM must be enabled with the _XRAMEN configuration variable in the startup code (START167.A66 or STARTV2.A66).
  • It is not possible to locate the system stack or register banks in the XRAM memory area (XRAM appears as external memory).
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