commit 9b61faab501fe15abd871f9d18249f1c620b1719
author Rupert Swarbrick <rswarbrick@lowrisc.org> Mon Nov 23 16:41:13 2020 +0000
committer Rupert Swarbrick <rswarbrick@gmail.com> Tue Nov 24 15:57:10 2020 +0000
tree 2b4a13e7c6cb2c97de544551dddf8a72190b2fea
parent 88a3835157492ebc16b501286214504e1a482404

[otbn] Minor tidy-ups in the WSR documentation

No big changes, but move the name of the WSR into a separate column in
the table (makes more sense and is slightly easier to read). Remove
the duplicated entry for the accumulator and shorten its text to
remove some repetition. Finally, link the instruction names.

Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>

hw/ip/otbn/doc/_index.md

diff --git a/hw/ip/otbn/doc/_index.md b/hw/ip/otbn/doc/_index.md
index 6b59958..595eafb 100644
--- a/hw/ip/otbn/doc/_index.md
+++ b/hw/ip/otbn/doc/_index.md
@@ -246,42 +246,45 @@
 
 ### Wide Special Purpose Registers (WSRs)
 
-In addition to the Wide Data Registers, BN instructions can also access WLEN-sized special purpose registers, short WSRs.
+OTBN has 256b Wide Special purpose Registers (WSRs).
+These are analogous to the 32b CSRs, but are used by big number instructions.
+They can be accessed with the [`BN.WSRRS`]({{< relref "hw/ip/otbn/doc/isa#bnwsrrs" >}}) and [`BN.WSRRW`]({{< relref "hw/ip/otbn/doc/isa#bnwsrrw" >}}) instructions.
 
 <table>
   <thead>
     <tr>
       <th>Number</th>
-      <th>Privilege</th>
+      <th>Name</th>
+      <th>R/W</th>
       <th>Description</th>
     </tr>
   </thead>
   <tbody>
     <tr>
       <td>0x0</td>
+      <td><strong>MOD</strong></td>
       <td>RW</td>
-      <td>
-        <strong>MOD</strong>
-        Modulus.
-        To be used in the BN.ADDM and BN.SUBM instructions.
-        This WSR is mapped to the MOD0 to MOD7 CSRs.
-      </td>
+<td>
+
+The modulus used by the [`BN.ADDM`]({{< relref "hw/ip/otbn/doc/isa#bnaddm" >}}) and [`BN.SUBM`]({{< relref "hw/ip/otbn/doc/isa#bnsubm" >}}) instructions.
+This WSR is also visible as CSRs `MOD0` through to `MOD7`.
+
+</td>
     </tr>
     <tr>
       <td>0x1</td>
+      <td><strong>RND</strong></td>
       <td>R</td>
       <td>
-        <strong>RND</strong>
         A random number.
       </td>
     </tr>
     <tr>
       <td>0x2</td>
+      <td><strong>ACC</strong></td>
       <td>RW</td>
       <td>
-        <strong>ACC</strong>
-        MAC Accumulator.
-        This gives direct access to the accumulator register used by the BN.MULQACC instruction.
+        The accumulator register used by the BN.MULQACC instruction.
       </td>
     </tr>
   </tbody>
@@ -314,10 +317,6 @@
 Each loop stack entry is a tuple of loop count, start address, and end address.
 The number of entries in the loop stack is implementation-dependent.
 
-### Accumulator
-
-A WLEN bit wide accumulator used by the BN.MULQACC instruction.
-
 # Theory of Operations
 
 ## Block Diagram