Level-trigger on TTO_FLAG instead of edge-trigger.

2 files changed, 3 insertions, 4 deletions

diff --git a/isa/decode.cpp b/isa/decode.cpp
index c11679c..1496364 100644
--- a/isa/decode.cpp
+++ b/isa/decode.cpp
@@ -185,7 +185,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
                             inst.read_ctlreg = TT_BITS;
                             inst.write_ctlreg = TT_BITS;
                             inst.ef = [](auto &ctx) {
-                                ctx.ctlval.value() |= TTO_FLAG | TTO_FLAG_OLD;
+                                ctx.ctlval.value() |= TTO_FLAG;
                             };
                             break;
                         case 1:
@@ -202,7 +202,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
                             inst.read_ctlreg = TT_BITS;
                             inst.write_ctlreg = TT_BITS;
                             inst.ef = [](auto &ctx) {
-                                ctx.ctlval.value() &= ~TTO_FLAG & ~TTO_FLAG_OLD;
+                                ctx.ctlval.value() &= ~TTO_FLAG;
                             };
                             break;
                         case 4:
@@ -235,7 +235,7 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit
                             inst.ef = [](auto &ctx) {
                                 auto &x = ctx.ctlval.value();
                                 auto chr = ctx.acc.value();
-                                x &= ~TTO_FLAG & ~TTO_FLAG_OLD & ~TTO_DATA;
+                                x &= ~TTO_FLAG & ~TTO_DATA;
                                 x |= (chr << TTO_DATA_SHIFT) & TTO_DATA;
                                 x |= TTO_TX;
                             };
diff --git a/isa/isa.h b/isa/isa.h
index 6484cd8..69f8b2a 100644
--- a/isa/isa.h
+++ b/isa/isa.h
@@ -30,7 +30,6 @@ const std::map<std::string, ctlreg> ctlreg_map = {
 static constexpr std::uint_fast32_t TTI_FLAG = 1 << 0;
 static constexpr std::uint_fast32_t TTO_TX = 1 << 1;
 static constexpr std::uint_fast32_t TTO_FLAG = 1 << 2;
-static constexpr std::uint_fast32_t TTO_FLAG_OLD = 1 << 3;
 static constexpr unsigned int TTI_DATA_SHIFT = 8;
 static constexpr unsigned int TTO_DATA_SHIFT = 16;
 static constexpr std::uint_fast32_t TTI_DATA = 0xff << TTI_DATA_SHIFT;