[rom_ctrl,doc] Expand description of block parameters

This now lists all the parameters that get passed into the block and describes things a bit more helpfully. Signed-off-by: Rupert Swarbrick <[email protected]>
lowRISC · Feb 12, 2025 · a3a4ff6 · a3a4ff6
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commit a3a4ff6
Showing 1 changed file with 17 additions and 4 deletions.
diff --git a/hw/ip/rom_ctrl/doc/interfaces.md b/hw/ip/rom_ctrl/doc/interfaces.md
@@ -53,10 +53,23 @@ Referring to the [Comportable guideline for peripheral device functionality](htt
 
 ## Parameters
 
-Parameter                   | Default (Max)         | Top Earlgrey | Description
-----------------------------|-----------------------|--------------|---------------
-`RndCnstRomKey`             | (see RTL)             | (see RTL)    | Compile-time random default constant for scrambling key (used in `prim_prince` block).
-`RndCnstRomNonce`           | (see RTL)             | (see RTL)    | Compile-time random default constant for scrambling nonce (used in `prim_prince` block and the two S&P blocks).
+The top-level `rom_ctrl` module has several parameters, although some of them are only relevant for verification.
+Those parameters are described separately below.
+The parameters that have an effect on the generated block are:
+
+Parameter         | Default (Max)                 | Top Earlgrey                                       | Description
+------------------|-------------------------------|----------------------------------------------------|---------------
+`AlertAsyncOn`    | True                          | True                                               | This is passed to the single `prim_alert_sender` instance and causes it to generate synchronization logic to support alert rx and tx being on different clocks.
+`RndCnstRomNonce` | `RND_CNST_SCR_NONCE` (define) | `top_earlgrey_rnd_cnst_pkg::RndCnstRomCtrlScrNonce`| Compile-time random default constant for scrambling nonce (used in `prim_prince` block and the two S&P blocks).
+`RndCnstRomKey`   | `RND_CNST_SCR_KEY` (define)   | `top_earlgrey_rnd_cnst_pkg::RndCnstRomCtrlScrKey`  | 128-bit compile-time random default constant for scrambling key (used in `prim_prince` block).
+`MemSizeRom`      | 64kB                          | 32kB                                               | The size of the ROM itself
+
+The parameters that are only used at verification time are:
+
+Parameter                   | Description
+----------------------------|---------------
+`BootRomInitFile`           | This is the path of a vmem file that can be loaded to populate the ROM in a test. Used for FPGA testing.
+`SecDisableScrambling`      | A flag that tells `rom_ctrl` not to scramble its backing memory. The result is less secure, but much smaller (used for `top_englishbreakfast`)
 
 ## Signals