dm3730 ddr 主频设置问题

/* Issi part of 3430 EVM (165MHz optimized) 6.06ns
					 *   ACTIMA
					 *	TDAL = Twr/Tck + Trp/tck = 15/6 + 18 /6 = 2.5 + 3 = 5.5 -> 6
					 *	TDPL (Twr) = 15/6	= 2.5 -> 3
					 *	TRRD = 12/6	= 2
					 *	TRCD = 18/6 = 3
					 *	TRP = 18/6	= 3
					 *	TRAS = 42/6	= 7
					 *	TRC = 60/6	= 10
					 *	TRFC = 72/6	= 12
					 *   ACTIMB
					 *	TWTR =  2
					 *	TCKE =  1
					 *	TXSR =  120/6  = 20
					 *	TXP  =  1   
					 */
					 #define ISSI_TDAL_165   6
					#define ISSI_TDPL_165   3
					#define ISSI_TRRD_165   2
					#define ISSI_TRCD_165   3
					#define ISSI_TRP_165    3
					#define ISSI_TRAS_165   7
					#define ISSI_TRC_165   10
					#define ISSI_TRFC_165  12
					#define ISSI_V_ACTIMA_165 ((ISSI_TRFC_165 << 27) | (ISSI_TRC_165 << 22) | (ISSI_TRAS_165 << 18) \
							| (ISSI_TRP_165 << 15) | (ISSI_TRCD_165 << 12) |(ISSI_TRRD_165 << 9) | \
							(ISSI_TDPL_165 << 6) | (ISSI_TDAL_165))
					
					#define ISSI_TWTR_165   2
					#define ISSI_TCKE_165   1
					#define ISSI_TXP_165    1
					#define ISSI_XSR_165    20
					#define ISSI_V_ACTIMB_165 ((ISSI_TCKE_165 << 12) | (ISSI_XSR_165 << 0)) | \
									(ISSI_TXP_165 << 8) | (ISSI_TWTR_165 << 16)