16.12.2.2 Operation From a Debug Adapter
Debug adapters should access the DSU registers in the external address range [0x0100 – 0x1FFF].
If DAL.CPU0 is equal to 0 or 3, accessing the first 0x100 bytes causes the DSU bus matrix to return an error to the DAP. See the following table for information.
| DBG Connection | DAL.CPU0 | DAP transaction allowed? | ||
|---|---|---|---|---|
| DSU internal address space | DSU external address space | Other | ||
| Cold-p | 0,3 | N (BE) | Y | N (BE) |
| Hot-p | 0,3 | N (APD) | ||
| any | 2 | Y | ||
BE: A Bus Error is sent back to the DAP setting its sticky bit error.
APD: Access port disabled. The transaction is discarded, the Debug Port (DP) sticky bit error is set.
Note: Refer to the ARM Debug Interface
Architecture Specification for details.