--- a/target-utils/simtest/simregs.h	Sat Feb 09 08:09:32 2019 +0000
+++ b/target-utils/simtest/simregs.h	Sat Feb 09 17:15:57 2019 +0000
@@ -15,3 +15,53 @@
 };
 
 #define	SIMREGS	(*(volatile struct sim_registers *) SIM_BASE_ADDR)
+
+/*
+ * Bit definitions 
+ */ 
+// control regidter
+#define SIM_CMD_CRST          0x0001
+#define SIM_CMD_SWRST         0x0002
+#define SIM_CMD_STOP          0x0004
+#define SIM_CMD_START         0x0008
+#define SIM_CMD_CLKEN         0x0010	
+
+// status register
+#define SIM_STAT_CD           0x0001   // card present
+#define SIM_STAT_TXPAR        0x0002   // transmit parity status
+#define SIM_STAT_FFULL        0x0004   // fifo full
+#define SIM_STAT_FEMPTY       0x0008   // fifo empty
+
+// configuration register
+#define SIM_CONF1_CHKPAR      0x0001   // enable receipt check parity
+#define SIM_CONF1_CONV        0x0002   // coding convention
+#define SIM_CONF1_TXRX        0x0004   // SIO line direction
+#define SIM_CONF1_SCLKEN      0x0008   // enable SIM clock
+#define SIM_CONF1_RSVD        0x0010   // reserved
+#define SIM_CONF1_SCLKDIV	  0x0020   // SIM clock frquency
+#define SIM_CONF1_SCLKLEV	  0x0040   // SIM clock idle level
+#define SIM_CONF1_ETU	      0x0080   // ETU period
+#define SIM_CONF1_BYPASS      0x0100   // bypass hardware timers
+#define SIM_CONF1_SVCCLEV     0x0200
+#define SIM_CONF1_SRSTLEV     0x0400
+#define SIM_CONF1_SIOLOW      0x8000   //force SIO to low level	 
+
+// interrupt status register
+#define SIM_IT_NATR           0x0001   // No answer to reset
+#define SIM_IT_WT             0x0002
+#define SIM_IT_ITOV           0x0004   
+#define SIM_IT_ITTX           0x0008   // Transmit
+#define SIM_IT_ITRX           0x0010   // Receipt
+
+#define SIM_IT_CD             0x0001   // Card insertion/extraction
+
+// interrupt mask register
+#define SIM_MASK_NATR         0x0001   // No answer to reset
+#define SIM_MASK_WT           0x0002
+#define SIM_MASK_OV           0x0004
+#define SIM_MASK_TX           0x0008   // Transmit
+#define SIM_MASK_RX           0x0010   // Receipt
+#define SIM_MASK_CD           0x0020   // Card insertion/extraction	
+
+// receveid byte register
+#define SIM_DRX_STATRXPAR     0x0100   // received byte parity status