From 1d1e0acb5b4494f7c1b041e24e5de4f0614a150b Mon Sep 17 00:00:00 2001
From: Ian C <ianc@noddybox.co.uk>
Date: Sun, 23 Apr 2023 08:24:31 +0800
Subject: Updated Z80 emulation

---
 include/z80.h | 43 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 34 insertions(+), 9 deletions(-)

(limited to 'include/z80.h')

diff --git a/include/z80.h b/include/z80.h
index ef24fd0..c9bd107 100644
--- a/include/z80.h
+++ b/include/z80.h
@@ -56,20 +56,30 @@ typedef signed char Z80Relative;
 typedef unsigned short Z80Word;
 
 
-/* A Z80 16-bit register.  To access the HI/LO component use the indexes
-   Z80_HI_WORD and Z80_LO_WORD which will be initialised once Z80Init has been
-   called.
+/* A Z80 16-bit register made up of 2 8-bit registers.
 */
+#ifdef Z80_LITTLE_ENDIAN
+typedef struct
+{
+    Z80Byte             lo;
+    Z80Byte             hi;
+} Z80RegPair;
+#endif
+
+#ifdef Z80_BIG_ENDIAN
+typedef struct
+{
+    Z80Byte             hi;
+    Z80Byte             lo;
+} Z80RegPair;
+#endif
+
 typedef union
 {
     Z80Word		w;
-    Z80Byte		b[2];
+    Z80RegPair          b;
 } Z80Reg;
 
-extern int Z80_HI_WORD;
-extern int Z80_LO_WORD;
-
-
 /* The processor
 */
 struct Z80Private;
@@ -134,13 +144,23 @@ typedef int	(*Z80Callback)(Z80 *cpu, Z80Val data);
 */
 typedef enum
 {
-    eZ80_Instruction,	/* data = no cycles since reset                       */
+    eZ80_Instruction,	/* data = cycles as returned by Z80Cycles             */
     eZ80_EDHook,	/* data = byte after ED opcode (only for NOP opcodes) */
     eZ80_Halt,		/* data = 1 halt raised, 0 halt cleared by int        */
     eZ80_RETI,		/* data = ignored                                     */
     eZ80_NO_CALLBACK	/* leave at end                                       */
 } Z80CallbackReason;
 
+/* Defines cycle timers
+*/
+typedef enum
+{
+    Z80_TIMER_1,
+    Z80_TIMER_2,
+    Z80_TIMER_3,
+    Z80_NO_TIMERS
+} Z80Timer;
+
 
 /* Flags in the F register
 */
@@ -235,6 +255,11 @@ void	Z80Exec(Z80 *cpu);
 Z80Val	Z80Cycles(Z80 *cpu);
 void	Z80ResetCycles(Z80 *cpu, Z80Val cycles);
 
+/* Timers that count in cycle counts
+*/
+Z80Val  Z80GetTimer(Z80 *cpu, Z80Timer timer);
+void    Z80SetTimer(Z80 *cpu, Z80Timer timer, Z80Val cycles);
+
 
 /* Set address to label mappings for the disassembler
 */
-- 
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