testflash.asm

本程序是实现DSP系统与上位机串口通讯的程序

;TL16C550 REGISTER SET IO ADDRESS  
;LCR:8003H    DIVISOR LATCH (LSB)=8000H 当DLAB=1时
;                        DIVISOR LATCH (MSB)=8001H 当DLAB=1时
;IER:8001H    IIR:8002H(READ ONLY)
;MCR:8004H  LSR:8005H    FCR:8002H(write only)
;RBR:8000H(READ ONLY)当DLAB=0时
;THR:8000H(WRITE ONLY)当DLAB=0时 

;8 BIT ODD PARITY 1 BIT STOP  9600BIT/S 
 
 .mmregs       
 .global  _Sendinit  
 .global  _Send  
 .global  _Recv
 .global  _DRDY
 .text     
_Sendinit:
;********************************************
;init dsp register
      nop
      STM    #0x7fff, SWWSR
      STM    #0x1800,ST0
	  stm    1000h,ar0
	  stm    1000h,ar1 
      stm    1000h,ar2	  
;********************************************
LL:   portr 800fh,ar2 ; read io 800fh,SET UART_MR=0,UART OUT RESET                              
      NOP   
      NOP     
      portr 8008h,ar2;read io 8008h,flash_enable=1,ram=enable
      nop
      nop    
UART:  portr  800fh,ar2 ; read io 800fh,SET UART_MR=0,UART OUT RESET
       nop
       nop
       STM    83H,AR1  ; READY TO WRITE THE DIVISOR 8 BIT 1 STOP ODD PARITY   
       PORTW  AR1,8003H ;WRITE  16C550 LCR A2=0,A1=1,A0=1 
                        ;READY TO WRITE THE DIVISOR 8 BIT 1 STOP ODD PARITY
                        ;DLAB=1 ,STICK PARITY BIT DISANBLE
       nop
       nop
       portr  8003h,ar2 ;check 8013h register
       nop
       nop
       STM    18H,AR1 
       PORTW  AR1,8000H ;Divisor latch (LSB)=18H
       nop
       nop
       portr 8000h,ar2 ;check 8010h register
       nop
       nop
       STM    00,AR1
       PORTW  AR1,8001H ;Divisor latch (MSB)=00H
                        ;SET Baud Rates=9600BIT/S 
       nop
       nop
       portr 8001h,ar2 ;check 8011h register
       nop
       nop
       STM    03H,AR1
       PORTW  AR1,8003H ;SET LCR DLAB=0  enable read and write
       nop
       nop
       portr 8003h,ar2 ;check 8013h register
       nop
       nop
       STM    00H,AR1  
       PORTW  AR1,8002H ;SET  fcr  
       nop
       nop
       portr 8002h,ar2 ;check 8012h register
       nop
       nop
       PORTW  AR1,8001H ;SET  IER=00H DISABLE ALL INTERRUPT
       nop
       nop
       portr 8001h,ar2 ;check 8011h register
       nop
       nop
       PORTW  AR1,8004H ;SET  MCR=00H DTR=1,RTS=1 OUT1,2=1 diagnostic testing 
                        ;DISABLE 
       NOP
       nop
       portr 8004h,ar2 ;check 8014h register
       nop
       nop
       ret
;**********************************************************       
;star  send char
;********************************************************** 
_Send:      
WS:  
       nop
BB:   
       stm    03h,ar3 
       portw  ar3,8003h ;SET LCR DLAB=0  enable read and write
       NOP
       NOP 
       portr 8003h,ar2 ;check 8013h register
       NOP
       NOP 
WRITE: PORTW  AR7,8000H;begin  SEND CHAR
       NOP
       call wait;must be call dealy subprg
       nop
       stm   00h,ar2 ;can break here to see 8015h register
       nop
TEST:  PORTR  8005H,AR2 ;READ  LSR
       nop
       nop
       BITF   AR2,20H  ;TEST LSR.BIT(7)=1 ,transmit register empty or not?
       BC     TEST, NTC                                                                                                                                                                                
       NOP
       ret       
;***************************************************** 
;transmit end
;*****************************************************

;*****************************************************
;begin receive data
;*****************************************************
_Recv:
ff:    stm    03h,ar3
       portw  ar3,8003h ;SET LCR DLAB=0  enable read and write
       nop
       nop
       portr  8003h,ar2 ;check 8013h register
       nop
       nop    
       portr  8005h,ar5  ;READ  LSR
       nop
       nop
       bitf   ar5,01h   ;TEST LSR.BIT(1)=1? receive data?
       bc     ff,ntc
       portr  8000h,ar6 ;write receive data to 8000h data address
       NOP
       NOP
       ret  
*******************************************************  
_DRDY: nop
       nop
read:  nop
       nop
       bc  read,bio
       nop
       nop
       ret
     
wait: 
	  stm   010h,ar3              
loop1:stm 	020h,ar4
loop2:banz 	loop2,*ar4-
	  banz 	loop1,*ar3- 
	  nop          
      ret                       	  
.end