core, add TH pad pin latency after switching to input

diff --git a/pico/memory.c b/pico/memory.c
index 1fbb47b..860dfed 100644 (file)
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -314,6 +314,8 @@ static port_read_func *port_readers[3] = {
   read_nothing\r
 };\r
 \r
+static int padTHLatency[3];\r
+\r
 static NOINLINE u32 port_read(int i)\r
 {\r
   u32 data_reg = PicoMem.ioports[i + 1];\r
@@ -326,10 +328,8 @@ 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
-  if (PicoIn.AHW & (PAHW_32X|PAHW_MCD)) // don't do it on 32X, it breaks WWF Raw\r
-    out |= 0x7f & ~ctrl_reg;\r
-  else\r
-    out |= 0x3f & ~ctrl_reg;\r
+  u32 mask = 0x3f | (padTHLatency[i] < SekCyclesDone() ? 0x40 : 0);\r
+  out |= mask & ~ctrl_reg;\r
 \r
   in = port_readers[i](i, out);\r
 \r
@@ -407,6 +407,11 @@ 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
+\r
   // certain IO ports can be used as RAM\r
   PicoMem.ioports[a] = d;\r
 }\r