init_hdlc.asm

网络通信中2M专用HW线的高速串行接口的DSP C程序实现

;********************************************************************************
;*                                                                              *       
;*----------------北京高阳迪威科技有限公司深圳研究中心 -------------------------*
;*                                                                              *
;*  工程:       ASB板测试程序                                                   *
;*  版本:       V1.0                                                            *
;*                                                                              *
;*  作者:       LIN QIU FU                                                      *
;*  日期:       2001/6/8                                                        *
;*                                                                   *
;********************************************************************************
;*                                      
;*  文件描述:
;*              通用型子函数
;*              
;*              初始化sab82525 
;*
;*******************************************************
;
;
                .mmregs
;
; 包含文件:    
				.include "main.inc"
; 引用符号列表:
              
                                            
; 被引用符号列表
                       
               
                .def  init_sab82525   
               
                
; 代码:
                
                .text           

;初始化sab82525        
;**************************************************************
;*****************the initialization of SAB82525 ****************
;SAB82525 has a bug,to conquer it,the TSNX of Time_Slot Assignment Register
;Tranmit(TSAX) must be 1 less than the actual time slot,and,Clock Shift bit 
;XCS2,XCS1,XCS0 should be initialized with 7.the same for receival
init_sab82525:	
        pshm	SWWSR        
        stm		#7f00h,SWWSR

Command_Execute:
		stm		#B_STAR,ar2   
		nop
		nop   
		
		bit		*ar2,15-2 
		nop
		nop
       		;test STARb register bit2 CEC (Command Executing?)
		bc		Command_Execute,tc 
	
		stm		#B_CCR1,ar2
		nop
		nop
		st		#35h,*ar2   
;        ST      #0A5H,*AR2
          	;PU=0(standby), sc1 sc0=01(bus configuration,timemode1),clockmode5
		nop
		nop
		stm		#B_CCR2,ar2 
		nop
		nop
 		st		#38h,*ar2 
;        ST      #08H,*AR2
         	;SOC1 SOC0=00,XCS0 RCS0=11,TIO=1,CIE=0,RIE=0,DIV=0
		nop
		nop
		stm		#B_TSAX,ar2
		nop
		nop
;    	st		#07h,*ar2
    	ST      #7CH,*AR2
    	nop
    	nop
     
     		;TSNX=B(20 or 21) , XCS2 XCS1=11 (XCS0=1) =>transmit clock shift is 7
		stm		#B_TSAR,ar2
;    	st		#07h,*ar2 
        nop
        nop
        ST      #7CH,*AR2
    	nop
    	nop
 
            ;TSNR=B(20 or 21) , RCS2 RCS1=11 (RCS0=1) =>shift 7
		stm 	#B_XCCR,ar2                     
		nop
		nop 
		st		#07h,*ar2
          	;Num of bits to be transmitted with a timeslot = 7+1= 8
	
		nop
		nop
		stm		#B_RCCR,ar2
		nop
		nop       
		st		#07h,*ar2
          	;Num of bits to be received with a timeslot = 7+1= 8
		nop
		nop
		stm		#B_MASK,ar2                     
		nop
		nop
		st		#0ffH,*ar2     	;mask all a channel int.
	    nop
		nop 
		
		stm		#B_MASK,ar2
		nop
		nop        
;		st      #0ffh,*ar2
      	st      #038h,*ar2      ;enable RME,RPF,EXA,EXB
;        ST      #2FH,*AR2
               
		nop
		nop
		stm		#B_MODE,ar2     ;Transparent Mode 0, no address recognition , TMD=0 (external)
		nop
		nop
		st		#089h,*ar2     	;Loopback mode(internal)     
;        ST      #0A8H,*AR2	
;		st		#088h,*ar2
	
		nop
		nop
		stm		#B_RLCR,ar2
		nop
		nop
		st		#7fH,*ar2       ;receive length not check, 32*(1+1)=64 bytes
		
		nop
		nop
		stm		#B_XBCH,ar2
		nop
		nop
		st		#0,*ar2         ;DMA=0(Interrupt controlled transfer), CAS=0

		nop
		nop
		stm		#B_CMDR,ar2
		nop
		nop
		st		#041h,*ar2      ;RMC=1(Receive MSG Cmpt) , RHR=1(Rst HDLC rcver), XRES=1(Transmit Rst)
;        ST      #43H,*AR2
       
		nop
		nop
		stm		#B_CCR1,ar2
		nop
		nop
    	st      #0b5h,*ar2	    ;let PU=1 (Power up ---> active)
    	nop
    	nop
		stm		#B_STAR,ar2  
		nop
		nop
hdlc_active_b
;******************************************
		bit		*ar2,15-2

		bc		hdlc_active_b,tc  ; CEC =1?
;******************************************
		nop
		nop
		
        popm	SWWSR
	
		ret     
		

                
                .end