This register defines which MicroBlaze™ processor or processors are accessed. This register is a write-only register. Issuing a read request has no effect, and undefined data is read.
It is possible to write to the debug registers of more than one processor simultaneously, by setting more than one bit in this register. When reading from a debug register, only one bit must be set in this register, otherwise read data is undefined.
The register bit size is variable, and depends on the C_MB_DBG_PORTS parameter:
- When C_MB_DBG_PORTS set to 1, the register is not used, and the only connected processor is always accessed.
- When C_MB_DBG_PORTS ranges from 2 to 8, the register has 8 bits
- When C_MB_DBG_PORTS is greater than 8, the register has the same number of bits as the parameter
The processors are defined from the right in the register according to the following table.
| 31 | 8 | 7 | 0 |
| C_MB_DBG_PORTS | Bits | Access | Reset Value | Description |
|---|---|---|---|---|
| 2 | 1 - 0 | W | 0 |
Bit 0 = Access processor number 0 Bit 1 = Access processor number 1 |
| 3 | 2 - 0 | W | 0 |
Bit 0 = Access processor number 0 Bit 1 = Access processor number 1 Bit 2 = Access processor number 2 |
| ... | ... | ... | ... | ... |
| 8 | 7 - 0 | W | 0 |
Bit 0 = Access processor number 0 ... Bit 7 = Access processor number 7 |
| 8 - 32 | (n-1) - 0 | W | 0 |
Bit 0 = Access processor number 0 ... Bit n-1 = Access processor number n-1 |