core, add TH pad pin latency (regression after 5 min)

diff --git a/pico/memory.c b/pico/memory.c
index 860dfed..2ca6f2c 100644 (file)
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -328,7 +328,11 @@ static NOINLINE u32 port_read(int i)
   // disables output before doing TH-low read, so don't emulate it for TH.\r
   // Decap Attack reportedly doesn't work on Nomad but works on must\r
   // other MD revisions (different pull-up strength?).\r
-  u32 mask = 0x3f | (padTHLatency[i] < SekCyclesDone() ? 0x40 : 0);\r
+  u32 mask = 0x3f;\r
+  if (CYCLES_GE(SekCyclesDone(), padTHLatency[i])) {\r
+    mask |= 0x40;\r
+    padTHLatency[i] = SekCyclesDone();\r
+  }\r
   out |= mask & ~ctrl_reg;\r
 \r
   in = port_readers[i](i, out);\r
@@ -407,10 +411,13 @@ NOINLINE void io_ports_write(u32 a, u32 d)
       Pico.m.padTHPhase[a - 1]++;\r
   }\r
 \r
-  // after pulling down TH there's a latency before the new value can be read\r
-  // back as input (see Decap Attack, not in Samurai Showdown, 32x WWF Raw)\r
-  if (a >= 4 && a <= 5 && !(d & 0x40))\r
-    padTHLatency[a - 4] = SekCyclesDone() + 25;\r
+  // after switching TH to input there's a latency before the pullup value is \r
+  // read back as input (see Decap Attack, not in Samurai Showdown, 32x WWF Raw)\r
+  if (a >= 4 && a <= 5) {\r
+    padTHLatency[a - 4] = SekCyclesDone(); // if output, effective immediately\r
+    if ((PicoMem.ioports[a] & 0x40) && !(d & 0x40))\r
+      padTHLatency[a - 4] += 25; // latency after switching to input\r
+  }\r
 \r
   // certain IO ports can be used as RAM\r
   PicoMem.ioports[a] = d;\r