a per-implementor basis.
Where the opcode is normally loaded from the location at the PC, the extra
-bits are instead set via a CSR and mandatorially appended to every instruction: hence why they are described as "hidden" opcode bits, and as a "namespace".
+bits, set via a CSR, are mandatorially appended to every instruction: hence why they are described as "hidden" opcode bits, and as a "namespace".
The parallels with c++ "using namespace" are direct and clear.
<code>
<pre>
- 3 2 1
- |1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0|
- |------------------------------ |-------|---------------------|-|
- |reserved reserved reserved reserved reserved | foreignarch |1|
- |custom | reserved | official|B| rvcpage |0|
+ 3 2 1
+|1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0|
+|------------------------------ |-------|---------------------|-|
+|reserved reserved reserved reserved reserved | foreignarch |1|
+|custom | reserved | official|B| rvcpage |0|
</pre>
<code>