From: Hugo Villeneuve <hugo@hugovil.com>
Date: Mon, 18 Nov 2013 00:48:05 +0000 (-0500)
Subject: Add function to read 16-bit address/offset/value from pgm memory
X-Git-Tag: v2.0.0~80
X-Git-Url: http://gitweb.hugovil.com/?a=commitdiff_plain;h=ad5ac01289f23e38a1b14a33d4e98a1c5a6655f5;p=emu8051.git

Add function to read 16-bit address/offset/value from pgm memory
---

diff --git a/src/memory.c b/src/memory.c
index ac8bca5..67a9266 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -183,6 +183,18 @@ stack_pop16(void)
 	return value;
 }
 
+/* Read a 16-bit address from PGM memory, starting at <base> offset */
+uint16_t
+pgm_read_addr16(uint16_t base)
+{
+	uint16_t addr;
+
+	addr = memory_read8(PGM_MEM_ID, base) << 8; /* MSB */
+	addr |= memory_read8(PGM_MEM_ID, base + 1); /* LSB */
+
+	return addr;
+}
+
 /* Dump memory */
 void
 DumpMem(char *Address, char *Asize, int memory_id)
diff --git a/src/memory.h b/src/memory.h
index c8761e9..fee41a6 100644
--- a/src/memory.h
+++ b/src/memory.h
@@ -79,6 +79,9 @@ stack_pop8(void);
 uint16_t
 stack_pop16(void);
 
+uint16_t
+pgm_read_addr16(uint16_t base);
+
 void
 DumpMem(char *Address, char *Asize, int memory_id);
 
diff --git a/src/opcode2c.pl b/src/opcode2c.pl
index 270112a..035c718 100755
--- a/src/opcode2c.pl
+++ b/src/opcode2c.pl
@@ -231,8 +231,8 @@ for ($i=0 ; $i< 256; $i++) {
 		cfw("cpu8051.pc++;");
 	    }
 	    if ($op_destination == 1) { # addr16
-		cfw("unsigned int addr16 = ( memory_read8( PGM_MEM_ID, cpu8051.pc++ ) << 8 );");
-		cfw("addr16 += memory_read8( PGM_MEM_ID, cpu8051.pc++ );");
+		cfw("uint16_t addr16 = pgm_read_addr16(cpu8051.pc);");
+		cfw("cpu8051.pc += 2;");
 	    }
 	    if ($op_destination == 2) { # A
 		cfw("unsigned char destination = cpu8051_ReadD( _ACC_ );");
@@ -247,7 +247,6 @@ for ($i=0 ; $i< 256; $i++) {
 	    if ($op_destination == 5) { # @R1
 		cfw("unsigned char destination = cpu8051_ReadI ( cpu8051_ReadD( BANKPSW + _R1_ ) );");
 	    }
-
 	    if ($op_destination == 6) { # R0
 		cfw("unsigned char destination = cpu8051_ReadD( BANKPSW + _R0_ );");
 	    }
@@ -311,8 +310,8 @@ for ($i=0 ; $i< 256; $i++) {
 		cfw("unsigned int addr11 = ( ( memory_read8( PGM_MEM_ID, cpu8051.pc - 1 ) << 3 ) & 0xF00 ) + memory_read8( PGM_MEM_ID, (cpu8051.pc)++ );");
 	    }
 	    if ($op_source == 1) { # addr16
-		cfw("unsigned int addr16 = ( memory_read8( PGM_MEM_ID, (cpu8051.pc)++ ) << 8 );");
-		cfw("addr16 += memory_read8( PGM_MEM_ID, (cpu8051.pc)++ );");
+		cfw("uint16_t addr16 = pgm_read_addr16(cpu8051.pc);");
+		cfw("cpu8051.pc += 2;");
 	    }
 	    if ($op_source == 2) { # A
 		cfw("unsigned char source = cpu8051_ReadD( _ACC_ );");
@@ -376,8 +375,8 @@ for ($i=0 ; $i< 256; $i++) {
 		cfw("unsigned int source = memory_sfr_read_dptr();");
 	    }
 	    if ($op_source == 22) { # #data16
-		cfw("unsigned int source = ( memory_read8( PGM_MEM_ID, (cpu8051.pc)++ ) << 8 );");
-		cfw("source += memory_read8( PGM_MEM_ID, (cpu8051.pc)++ );");
+		cfw("uint16_t source = pgm_read_addr16(cpu8051.pc);");
+		cfw("cpu8051.pc += 2;");
 	    }
 	    if ($op_source == 23) { # /bitaddr
 		cfw("unsigned char source, srcbitaddr = memory_read8( PGM_MEM_ID, (cpu8051.pc)++ );");
@@ -390,7 +389,6 @@ for ($i=0 ; $i< 256; $i++) {
 
 ##############################################################################
 	$modifysrc=0;
-#    cfw("\n// Inserer le code ici\n\n";
 
 	# RR
 	if ($insttype[$i] == 3) {