-#define REG_NONE 0x00U
-#define REG_A 0x01U
-#define REG_X 0x02U
-#define REG_Y 0x04U
-#define REG_SREG_LO 0x08U
-#define REG_SREG_HI 0x10U
-#define REG_TMP1 0x20U
-#define REG_PTR1_LO 0x40U
-#define REG_PTR1_HI 0x80U
+#define REG_NONE 0x0000U
+#define REG_A 0x0001U
+#define REG_X 0x0002U
+#define REG_Y 0x0004U
+#define REG_TMP1 0x0008U
+#define REG_PTR1_LO 0x0010U
+#define REG_PTR1_HI 0x0020U
+#define REG_PTR2_LO 0x0040U
+#define REG_PTR2_HI 0x0080U
+#define REG_SREG_LO 0x0100U
+#define REG_SREG_HI 0x0200U
+#define REG_SAVE_LO 0x0400U
+#define REG_SAVE_HI 0x0800U
+#define REG_SP_LO 0x1000U
+#define REG_SP_HI 0x2000U
+
+
+/* Combined register defines */
+#define REG_PTR1 (REG_PTR1_LO | REG_PTR1_HI)
+#define REG_PTR2 (REG_PTR2_LO | REG_PTR2_HI)
+#define REG_SREG (REG_SREG_LO | REG_SREG_HI)
+#define REG_SAVE (REG_SAVE_LO | REG_SAVE_HI)
+#define REG_SP (REG_SP_LO | REG_SP_HI)