14.7.7. Host to target debug communications channel

The DBGTAP debugger can use the following sequence for sending data to the core:

  1. SCAN_N into the IR.

  2. 5 into the SCREG.

  3. EXTEST into the IR.

  4. Scan in 34 bits, the least significant 32 holding the word to be sent. At the same time, 34 bits were scanned out. If the nRetry flag is clear repeat this step again.

  5. Now the data has been written into the rDTR. Go to step 4 again for sending in more data.

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