The Trace Command Register (TCMDR) is used to issue commands to clear, start, or stop trace, as well as sample the number of trace items. This register is a write-only register. Issuing a read request has no effect, and undefined data is read. See the following figure and table.
Figure 1. Trace Command Register
| Bits | Name | Description | Reset Value |
|---|---|---|---|
| 3 | Clear | Clear trace status and empty the trace buffer | 0 |
| 2 | Start | Start trace immediately | 0 |
| 1 | Stop | Stop trace immediately | 0 |
| 0 | Sample | Sample the number of current items in the trace buffer | 0 |