From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 17 Jul 2020 20:50:36 +0000 (+0100)
Subject: comment explaining why not to call self.trap in PowerDecode2
X-Git-Tag: semi_working_ecp5~699^2
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=48e0200b35493d8ac63df555f1458416d9217a37;p=soc.git

comment explaining why not to call self.trap in PowerDecode2
---

diff --git a/src/soc/decoder/power_decoder2.py b/src/soc/decoder/power_decoder2.py
index 5abf8314..323e49a7 100644
--- a/src/soc/decoder/power_decoder2.py
+++ b/src/soc/decoder/power_decoder2.py
@@ -669,6 +669,8 @@ class PowerDecode2(Elaboratable):
 
         # set the trapaddr to 0x700 for a td/tw/tdi/twi operation
         with m.If(op.internal_op == MicrOp.OP_TRAP):
+            # *DO NOT* call self.trap here.  that would reset absolutely
+            # rverything including destroying read of RA and RB.
             comb += do.trapaddr.eq(0x70)    # addr=0x700 (strip first nibble)
 
         # TODO: get msr, then can do privileged instruction