serial.a51

at89c51cc03RS232引导程序

;*A**************************************************************************
; NAME:             serial.a51
;----------------------------------------------------------------------------
; REVISION:         $version: $
;----------------------------------------------------------------------------
; PURPOSE:          This file contains the serial routines
;
;----------------------------------------------------------------------------
; NOTES:
;
;****************************************************************************
; CHANGES:
; CC03 introduces binary transfer mode send_hex_byte changed to send_data_byte
;
;****************************************************************************


$TITLE      (*** Serial Routines ***)

SERIAL_MODULE       SEGMENT     CODE 


;_____ I N C L U D E S ____________________________________________________

$include (config.inc)
$include (register.inc)



;_____ M A C R O S ________________________________________________________

CR_CHAR     EQU 0Dh
LF_CHAR     EQU 0Ah


;_____ D E F I N I T I O N ________________________________________________

 
;_____ D E C L A R A T I O N ______________________________________________

PUBLIC      send_char, send_cr_lf, send_point
PUBLIC      send_data_byte
PUBLIC      get_char, get_byte, get_byte_binary
PUBLIC      autobaud


RSEG        SERIAL_MODULE

;*F***************************************************************************
; NAME:     send_char
;-----------------------------------------------------------------------------
; PARAMS:   ACC: character to send
;
; RETURN:
;
;-----------------------------------------------------------------------------
; PURPOSE:  send one character on the serial link
;
;*****************************************************************************
send_char:
    jnb     TI,send_char    ; wait Tx is ready
    clr     TI
    mov     SBUF,A          ; send character
    ret


;*F***************************************************************************
; NAME:     send_cr_lf
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:
;
;-----------------------------------------------------------------------------
; PURPOSE:  send a CR character followed by a LF character on the serial link
;
;*****************************************************************************
send_cr_lf:
    mov     A,#CR_CHAR      ; transmit 0Dh
    acall   send_char
    mov     A,#LF_CHAR      ; transmit 0Ah
    acall   send_char
    ret


;*F***************************************************************************
; NAME:     send_point
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:
;
;-----------------------------------------------------------------------------
; PURPOSE:  send a '.' character followed by CR/LF on the serial link
;
;*****************************************************************************
send_point:
    mov     A,#'.'
    acall   send_char
    acall   send_cr_lf
    ret


;*F***************************************************************************
; NAME:     send_data_byte
;-----------------------------------------------------------------------------
; PARAMS:   R7: character to send (&convert) store and send
;
; RETURN:   
;
;-----------------------------------------------------------------------------
; PURPOSE:  Send one data byte over the serial line
;           
;*****************************************************************************
send_data_byte:
    mov     A,R7

send_data_byte_ascii:
    swap    A
    acall   hex_to_asc      ; convert MSN
    acall   send_char       ; send MSN
    mov     A,R7
    acall   hex_to_asc      ; convert LSN
    acall   send_char       ; send LSN
    ret


;*F***************************************************************************
; NAME:     get_char
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:   ACC: character received
;
;-----------------------------------------------------------------------------
; PURPOSE:  wait one character is received on the serial link
;           echo this character on the line
;
;*****************************************************************************
get_char:
    jnb     RI,get_char     ; wait Rx is ready
    clr     RI
    mov     A,SBUF          ; read received data
    acall   send_char       ; echo
    ret

;*F***************************************************************************
; NAME:     get_byte_binary
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:   ACC: byte in binary format
;
;-----------------------------------------------------------------------------
; PURPOSE:  wait an a byte (1 character) from the serial link
;
;-----------------------------------------------------------------------------
; NOTE:    
;
;*****************************************************************************
get_byte_binary:
    jnb     RI,get_char     ; wait Rx is ready
    clr     RI
    mov     A,SBUF          ; read received data
    ; acall   send_char       ; echo -> In New Binary mode : No Echo
    ret

;*F***************************************************************************
; NAME:     get_byte
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:   ACC: byte in binary format
;
;-----------------------------------------------------------------------------
; PURPOSE:  wait an hexadecimal ascii byte (2 characters) from the serial link
;
;-----------------------------------------------------------------------------
; NOTE:     R6 modified by the routine without saving it
;
;*****************************************************************************
get_byte:
    acall   get_char        ; wait ascii MSB
    acall   asc_to_hex
    swap    A
    mov     R6,A
    acall   get_char        ; wait ascii LSB
    acall   asc_to_hex
    orl     A,R6            ; build byte
    ret



hex_to_asc:
    anl     A,#0Fh          ; keep nibble
    add     A,#90H
    da      A
    addc    A,#40H
    da      A
    ret


asc_to_hex:
    clr     C
    subb    A,#'0'
    cjne    A,#0Ah,asc_to_hex_1
asc_to_hex_1:
    jc      asc_to_hex_3
    add     A,#-7
    cjne    A,#10h,asc_to_hex_2
asc_to_hex_2:
    jc      asc_to_hex_3
    mov     A,#00h          ; bad ASCII, return 00h
asc_to_hex_3:
    ret


;*F***************************************************************************
; NAME:     autobaud
;-----------------------------------------------------------------------------
; PARAMS:
;
; RETURN:
;
;-----------------------------------------------------------------------------
; PURPOSE:  check speed reception of a 'U' char and program the baud
;           generator according to it
; 
;*****************************************************************************
$if BRG_IBG
autobaud:                       ; autobaud with internal baud rate generator
    anl     TCON,#0Fh
    mov     TMOD,#10h           ; timer 1 in 16 bits mode
    jb      P3.0,$              ; wait for start bit
    jnb     P3.0,$              ; wait for data bit 0 'H'
    setb    TR1                 ; start timer
    mov     R0,#02h
auto_bit:
    jb      P3.0,$              ; wait for data bit 1/3 'L'
    jnb     P3.0,$              ; wait for data bit 2/4 'H'
    djnz    R0,auto_bit
    jb      P3.0,$              ; wait for data bit 5 'L'
    jnb     P3.0,$              ; wait for data bit 6 'H'
    clr     TR1                 ; stop timer
    jb      P3.0,$              ; wait for data bit 7 'L'
    jnb     P3.0,$              ; wait for stop bit 'H'

    ; BRL = ~(T1 / 16) + 1
    ; T1 / 16 : 2 shift left and keep MSB
    mov     A,TH1
    anl     A,#00Fh
    mov     R0,A
    mov     A,TL1
    mov     A,TL1
    jnb     ACC.3,auto_correct  ; take care of round
    add     A,#010h
auto_correct:
    anl     A,#0F0h
    orl     A,R0
    swap    A                   ; ACC = T1 / 16
    ; ~() + 1
    cpl     A
    inc     A
    mov     BRL,A               ; set the reload register
    mov     SCON,#052h          ; TI= 1, RI= 0, uart mode 1  
    orl     PCON,#080h          ; SMOD1= 1
    mov     BDRCON,#01Fh        ; SPD= 1, BRR = 1
    ret
$endif  ; BRG_IBG

$if BRG_T2
autobaud:                       ; autobaud with timer 2
    mov     T2CON,#00h
	mov    	TL2, #00h           ; RLe Autobaud improvement first reset cpt
	mov     TH2, #00h
    jnb     P3.0,$              ; Check for '1' on RxD line: bug 0007 modification
    jb      P3.0,$              ; wait for start bit
    setb    TR2                 ; start timer
	jnb     P3.0,$              ; wait for data bit 0 'H'
	jb		TF2, autobaud       ; RLe: Timeout : Buggly UART Laptop
    jb      P3.0,$              ; wait for data bit 1 'L'
    jnb     P3.0,$              ; wait for data bit 2 'H'
	jb      P3.0,$              ; wait for data bit 3 'L'
    jnb     P3.0,$              ; wait for data bit 4 'H'
    jb      P3.0,$              ; wait for data bit 5 'L'
    jnb     P3.0,$              ; wait for data bit 6 'H'
	jb      P3.0,$              ; wait for data bit 7 'L'
    clr     TR2                 ; stop timer
    jnb     P3.0,$              ; wait for stop bit 'H'
	mov		R0, #7              ; RLe Modif: measure correction
dec_measure:
    dec     TL2                 ; remove one cycle of measurement
    mov     A,TL2
    cjne    A,#0FFh,next_dec
    dec     TH2                 ; remove 1 to TH2 if initially TL2 was equal 00h (TH2,TL2:0200h--> 01FFh)
next_dec:
	djnz		R0, dec_measure

TH2_00:
    mov     A,TH2
    mov     R6,A
    mov     A,TL2
    clr     C                   ; first multiply by 2
    rlc     A
    xch     A,R6
    rlc     A
    xch     A,R6
    add     A,TL2               ; and then add the original value
    xch     A,R6
    addc    A,TH2
    ;
    ; a,r6 = (a,r6)/64
    ;
    mov     R0,#6
div64:
    clr     C
    rrc     A
    xch     A,R6
    rrc     A
    xch     A,R6
    djnz    R0,div64
 
    cpl     A
    mov     RCAP2H,A
    mov     A,R6
    cpl     A
    mov     RCAP2L,A
           
    mov     SCON,#052h          ; serial port in 8 bits UART
    mov     T2CON,#034h         ; Timer2 in Baud rate Generator mode

    setb    TR2                 ; start Timer2
    ret
$endif  ; BRG_T2


END