📄 tr8051.asm
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;
; The following 8051 code demonstrates reading and writing 92's, 93's, 94's
; using universal data packets. It transmits the results to the serial port
; at 9600 bps.
;
EXTRN CODE(TOUCHRESET, DATA_IN, TOUCHBYTE)
;
DATA_BIT BIT P1.3 ; Touch Memory data.
GND_BIT BIT P1.4 ; Touch Memory ground.
;
PCON EQU 87H ; Define special purpose
MCON EQU 0C6H ; registers specific
TA EQU 0C7H ; to the DS5000.
;
BUFF EQU 900H ; Buffer in external memory.
;
CODE_SEG SEGMENT CODE ; Code is in this segment.
;
DSEG AT 20H
LO: DS 1 ; Low byte of CRC.
;
DSEG AT 30H
HI: DS 1 ; High byte of CRC.
STACK: DS 1 ; Stack starts after data.
;
CSEG AT RESET ; Power on reset vector.
LJMP START ; Program begins here.
;
RSEG CODE_SEG ; Code segment begins here.
START:
MOV TA, #0AAH ; Timed
MOV TA, #55H ; access.
MOV PCON, #0 ; Disable watchdog timer.
MOV TA, #0AAH ; Timed
MOV TA, #55H ; access.
ORL MCON, #2 ; Enable partition access.
MOV MCON, #12H ; Set partition at 800H.
MOV TA, #0AAH ; Timed
MOV TA, #55H ; access.
ANL MCON, #0FDH ; Disable partition access.
;
MOV SP, #STACK-1 ; Reset the stack pointer.
CLR GND_BIT ; Touch Memory ground level.
;
CLR TR1 ; Stop the serial timer.
MOV TH1, #0FAH ; Set for 9600 bps when using
MOV TL1, #0FAH ; a 11.0592 MHz crystal.
ANL TMOD, #0FH ; Set timer for the eight
ORL TMOD, #20H ; bit auto-reload mode.
ORL PCON, #80H ; Set double bit rate.
MOV SCON, #52H ; Setup the serial port.
SETB TR1 ; Start the serial timer.
MAIN_LOOP:
JB DATA_BIT, $ ; Wait for presence start.
JNB DATA_BIT, $ ; Wait for presence end.
CALL KEYMACRO ; *** Try to read Touch Memory.
JNC MAIN_LOOP ; No valid packet, try again.
LJMP SPILLIT ; Send valid data packet to CPU.
SJMP MAIN_LOOP ; Look for touch memory.
SPILLIT:
MOV DPTR, #BUFF ; Initialize the data pointer.
MOV B, #1 ; Assume short string.
MOVX A, @DPTR ; Get string length.
INC DPTR ; Increment data pointer.
CJNE A, #0FFH, LA ; Branch if short string.
INC B ; Set for long string.
MOVX A, @DPTR ; Get string length - 255.
INC DPTR ; Increment data pointer.
LA:
PUSH B ; Set long or short string.
MOV B, A ; Set character count.
SJMP LC ; Start getting characters.
LB:
PUSH B ; Set long or short string.
MOV B, #0FFH ; Do 255 more characters.
LC:
MOVX A, @DPTR ; Get a character.
INC DPTR ; Increment data pointer.
JNB TI, $ ; Wait until transmitter not busy.
MOV SBUF, A ; Send out character in accumulator.
CLR TI ; Indicate transmitter bust.
DJNZ B, LC ; Go transmit next character.
POP B ; Get extended length.
DJNZ B, LB ; Go get next group of 255.
CALL GO_AWAY ; *** Wait for part to leave.
LJMP MAIN_LOOP ; Wait for next touch.
;
;********************************************************************
;
; Procedure KeyMacro
;
; This procedure executes a debounced call to GetData
; and returns with the Carry cleared or set according
; to the result of GetData.
;
KEYMACRO:
MOV B, #255 ; Number of trys allowed.
KEYLA:
CALL GETDATA ; Try to read the data.
JC KEYLB ; Continue if successful.
DJNZ B, KEYLA ; Otherwise try again.
KEYLB:
RET ; Return.
;
; Procedure Go_Away
;
; This procedure insures that the Touch Memory is gone
; before returning so that it will not be read more than
; once.
;
GO_AWAY:
MOV B, #128 ; Number of trys allowed.
GO:
CALL TOUCHRESET ; See if there's a part
JC GO_AWAY ; Wait while there is.
DJNZ B, GO ; Count while there's not.
RET ; Return.
;
; Procedure GetData
;
; This procedure should be called to attempt to read the
; data from a Touch Memory after a presence pulse is
; received on the one-wire bus. It attempts to read a
; string of characters from the Touch Memory into a RAM
; buffer and check the CRC16 which follows the string.
; If the CRC is correct, the procedure returns with the
; Carry bit set, indicating that the string in the RAM
; buffer is ready for output. The first byte in the RAM
; buffer is the number of subsequent characters to be
; output. If the Carry is cleared, then the attempt to
; read the Touch Memory was unsuccessful.
;
GETDATA:
PUSH B ; Save the try count.
CALL TOUCHRESET ; Send out reset signal.
JNC SA ; Abort if no presence.
SJMP PD ; Skip jump.
SA:
LJMP ABORT ; Take the hike to abort.
PD:
MOV A, #33H ; Get read rom command in accumulator.
CALL TOUCHBYTE ; Command to read the ROM.
CALL DATA_IN ; Read the family code.
CALL TOUCHRESET ; Restart at beginning.
JNC ABORT ; Abort if no presence.
CJNE A, #8, NOT_1992 ; Branch if not a DS1992.
MOV B, #126 ; Max string length is 125.
SJMP CONT
NOT_1992:
MOV B, #0 ; Max string length is 508.
CJNE A, #6, NOT_1993 ; Branch if not a DS1993.
SJMP CONT
NOT_1993:
CJNE A, #4, ABORT ; Abort if not a DS1994.
CONT:
MOV A, #0CCH
CALL TOUCHBYTE ; Skip over ROM section.
MOV A, #0F0H
CALL TOUCHBYTE ; Command to read the RAM.
CLR A
CALL TOUCHBYTE ; First address byte zero.
CLR A
CALL TOUCHBYTE ; Second address byte zero.
FINISH:
MOV LO, #0 ; Initialize the CRC accumulator
MOV HI, #0 ; with the starting page number.
MOV DPTR, #BUFF ; Point to start of buffer.
CALL GET_BYTE ; Read the string length.
INC B ; Prepare to test B for zero.
DJNZ B, BNZ ; Branch if B not zero.
CJNE A, #0FFH, ANZ
MOVX @DPTR, A ; Store zero for extended length.
INC DPTR ; Increment buffer pointer.
CALL GET_BYTE ; Get the length - 256.
JZ ANZ ; Branch if length = 256.
CJNE A, #254, $+3 ; Check the string length.
JNC ABORT ; Branch if length > 508.
MOV B, #2 ; Setup to read long string.
SJMP SIZE ; Set string size and go.
ABORT:
CLR C ; Indicate failure.
POP B ; Retrieve the try count.
RET ; Return.
BNZ:
JZ ABORT ; Abort if string too long.
CJNE A, B, $+3 ; Check size of string.
JNC ABORT ; Abort if string too long.
ANZ:
MOV B, #1 ; Setup to read short string.
SIZE:
PUSH B ; Store string size byte.
MOV B, A ; Set string length.
MOVX @DPTR, A ; First byte in buffer is length.
INC DPTR ; Increment buffer pointer.
SJMP IN_LOOP ; Go input the string.
BIG_LOOP:
PUSH B ; Save loop count.
MOV B, #0FFH ; Set for next group.
IN_LOOP:
CALL GET_BYTE ; Get a character.
MOVX @DPTR, A ; Store it in the buffer.
INC DPTR ; Increment buffer pointer.
DJNZ B, IN_LOOP ; Go for next character.
POP B ; Check high byte of count.
DJNZ B, BIG_LOOP ; Go for next character.
CALL GET_BYTE ; Include the CRC in
CALL GET_BYTE ; the CRC calculation.
MOV A, HI ; Check high byte of CRC.
CJNE A, #0B0H, ABORT ; Abort if it is wrong.
MOV A, LO ; Check low byte of CRC.
CJNE A, #001H, ABORT ; Abort if it is wrong.
SUCCESS:
SETB C ; Indicate successful read.
POP B ; Retrieve the try count.
RET ; Return.
;
; This procedure takes the byte received from DATA_IN and calculates the
; cummulative CRC16.
;
GET_BYTE:
CALL DATA_IN
CRC16:
PUSH ACC ; Save the character.
XRL A, LO ; Xor accumulator with val. in LO.
MOV LO, HI ; Put high byte of crc in its dest.
MOV HI, A ; Save data xor low(crc) for later
MOV C, P ; Get parity bit in carry.
JNC CRC0 ; Don't XRL if carry clear.
XRL LO, #01h ; Add the parity to crc bit 0
CRC0:
RRC A ; Get the low bit in c
JNC CRC1 ; Don't XRL if carry clear.
XRL LO, #40h ; Need to fix bit 6 of the result
CRC1:
MOV C, ACC.7 ; Get msb of accumulator in carry.
XRL A, HI ; Compute the results for bits P...U
RRC A ; Shift them into place
MOV HI, A ; And save them
JNC CRC2 ; Don't flip msb LO if carry clear.
CPL LO.7 ; Now clean up bit 7
CRC2:
POP ACC ; Restore the character.
RET ; Return to caller.
;
END ; End of Program.⌨️ 快捷键说明
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