Assign the now official marchid 37

robotman2412 · Jan 1, 2024 · 05159cc · 05159cc
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -36,7 +36,7 @@ With the following CSRs present, all mandatory:
 | `0x342`     | `mcause`     | `0x0000_0000` | WARL trap and exception cause
 | `0x343`     | `mtval`      | `0x0000_0000` | (unimplemented)
 | `0xf11`     | `mvendorid`  | `0x0000_0000` | (unimplemented)
-| `0xf12`     | `marchid`    | `0x0000_0022` | Serves as attribution for tapeouts and FPGA bitstreams (currently [applying for this value](https://github.com/riscv/riscv-isa-manual/pull/1181))
+| `0xf12`     | `marchid`    | `37`          | Serves as attribution for tapeouts and FPGA bitstreams
 | `0xf13`     | `mipid`      | `0x0000_0000` | (unimplemented)
 | `0xf14`     | `mhartid`    | parameter     | Read-only query of CPU/HART ID
 | `0xf15`     | `mconfigptr` | `0x0000_0000` | (unimplemented)

diff --git a/hdl/boa32_cpu.sv b/hdl/boa32_cpu.sv
@@ -587,7 +587,9 @@ module boa32_csrs#(
     // CSR mvendorid: M-mode vendor ID.
     wire [31:0] csr_mvendorid   = 0;
     // CSR mvendorid: M-mode architecture ID.
-    wire [31:0] csr_marchid     = 34;
+    // This CSR serves as attribution for tapeouts and FPGAs.
+    // It must not be modified and must be readable to any M-mode software.
+    wire [31:0] csr_marchid     = 37;
     // CSR mvendorid: M-mode implementation ID.
     wire [31:0] csr_mipid       = 0;
     // CSR mvendorid: M-mode implementation ID.