From: Hugo Villeneuve <hugo@hugovil.com>
Date: Sun, 17 Nov 2013 19:29:25 +0000 (-0500)
Subject: Add carry bit definitions
X-Git-Tag: v2.0.0~88
X-Git-Url: http://gitweb.hugovil.com/?a=commitdiff_plain;h=d1c1972f26e9eedcf02b56f10450bd1cb3c61d52;p=emu8051.git

Add carry bit definitions
---

diff --git a/src/psw.c b/src/psw.c
index 2210d85..bf75854 100644
--- a/src/psw.c
+++ b/src/psw.c
@@ -28,9 +28,9 @@ psw_write_cy(int cy)
 	u_int8_t psw = memory_read8(INT_MEM_ID, _PSW_);
 
 	if (cy)
-		psw |= 0x80;  /* Set */
+		psw |= PSW_FLAG_CY;  /* Set */
 	else
-		psw &= ~0x80; /* Clear */
+		psw &= ~PSW_FLAG_CY; /* Clear */
 
 	memory_write8(INT_MEM_ID, _PSW_, psw); /* Save updated value */
 }
@@ -40,7 +40,7 @@ psw_set_cy(void)
 {
 	u_int8_t psw = memory_read8(INT_MEM_ID, _PSW_);
 
-	psw |= 0x80;
+	psw |= PSW_FLAG_CY;
 
 	memory_write8(INT_MEM_ID, _PSW_, psw); /* Save updated value */
 }
@@ -50,7 +50,7 @@ psw_clr_cy(void)
 {
 	u_int8_t psw = memory_read8(INT_MEM_ID, _PSW_);
 
-	psw &= ~0x80;
+	psw &= ~PSW_FLAG_CY;
 
 	memory_write8(INT_MEM_ID, _PSW_, psw); /* Save updated value */
 }
@@ -59,5 +59,5 @@ psw_clr_cy(void)
 int
 psw_read_cy(void)
 {
-	return memory_read8(INT_MEM_ID, _PSW_) >> 7;
+	return memory_read8(INT_MEM_ID, _PSW_) >> PSW_BIT_CY;
 }
diff --git a/src/reg8051.h b/src/reg8051.h
index 1800be7..b484246 100644
--- a/src/reg8051.h
+++ b/src/reg8051.h
@@ -62,4 +62,14 @@
 #define _BANK2_     0x10
 #define _BANK3_     0x18
 
+#define PSW_BIT_CY 7
+#define PSW_BIT_AC 6
+#define PSW_BIT_OV 2
+#define PSW_BIT_P  0
+
+#define PSW_FLAG_CY (1 << PSW_BIT_CY)
+#define PSW_FLAG_AC (1 << PSW_BIT_AC)
+#define PSW_FLAG_OV (1 << PSW_BIT_OV)
+#define PSW_FLAG_P  (1 << PSW_BIT_P)
+
 #endif /* REG8051_H */