From 6b27889b992b1aea26b2688fd541d41dc53e99d6 Mon Sep 17 00:00:00 2001
From: Angelo Salese <angelosa@users.noreply.github.com>
Date: Tue, 24 Mar 2009 14:00:22 +0000
Subject: [PATCH] Added a preliminary implementation for the SLEEP opcode in
 SH-4 cpu. This fixes Quiz Keitai Q Mode booting [Angelo Salese]

---
 src/emu/cpu/sh4/sh4.c     | 11 ++++++++++-
 src/emu/cpu/sh4/sh4comn.c |  6 ++++--
 src/emu/cpu/sh4/sh4comn.h |  2 ++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/emu/cpu/sh4/sh4.c b/src/emu/cpu/sh4/sh4.c
index 03ef3f4cba8..9194a76d94a 100644
--- a/src/emu/cpu/sh4/sh4.c
+++ b/src/emu/cpu/sh4/sh4.c
@@ -1546,9 +1546,17 @@ INLINE void SHLR16(SH4 *sh4, UINT32 n)
 /*  SLEEP */
 INLINE void SLEEP(SH4 *sh4)
 {
-	sh4->pc -= 2;
+	/* 0 = normal mode */
+	/* 1 = enters into power-down mode */
+	/* 2 = go out the power-down mode after an exception */
+	if(sh4->sleep_mode != 2)
+		sh4->pc -= 2;
 	sh4->sh4_icount -= 2;
 	/* Wait_for_exception; */
+	if(sh4->sleep_mode == 0)
+		sh4->sleep_mode = 1;
+	else if(sh4->sleep_mode == 2)
+		sh4->sleep_mode = 0;
 }
 
 /*  STC     SR,Rn */
@@ -3317,6 +3325,7 @@ static CPU_RESET( sh4 )
 
 	sh4->internal_irq_level = -1;
 	sh4->irln = 15;
+	sh4->sleep_mode = 0;
 }
 
 /* Execute cycles - returns number of cycles actually run */
diff --git a/src/emu/cpu/sh4/sh4comn.c b/src/emu/cpu/sh4/sh4comn.c
index 75e0b0fae8f..bd888fcd1e8 100644
--- a/src/emu/cpu/sh4/sh4comn.c
+++ b/src/emu/cpu/sh4/sh4comn.c
@@ -212,6 +212,8 @@ void sh4_exception(SH4 *sh4, const char *message, int exception) // handle excep
 
 	/* fetch PC */
 	sh4->pc = sh4->vbr + vector;
+	/* wake up if a sleep opcode is triggered */
+	if(sh4->sleep_mode == 1) { sh4->sleep_mode = 2; }
 }
 
 static UINT32 compute_ticks_refresh_timer(emu_timer *timer, int hertz, int base, int divisor)
@@ -644,9 +646,9 @@ WRITE32_HANDLER( sh4_internal_w )
 	case MMUCR: // MMU Control
 		if (data & 1)
 			fatalerror("SH4: MMUCR write enables MMU\n");
-	
+
 		break;
-	
+
 		// Memory refresh
 	case RTCSR:
 		sh4->m[RTCSR] &= 255;
diff --git a/src/emu/cpu/sh4/sh4comn.h b/src/emu/cpu/sh4/sh4comn.h
index ed3c541bf40..87df6d90d9f 100644
--- a/src/emu/cpu/sh4/sh4comn.h
+++ b/src/emu/cpu/sh4/sh4comn.h
@@ -68,6 +68,8 @@ typedef struct
 	UINT32	*m;
 	INT8	nmi_line_state;
 
+	UINT8 sleep_mode;
+
 	int		frt_input;
 	int		irln;
 	int 	internal_irq_level;