C51 source program for keystrokes

96-key zero-delay acquisition
 
 
HotPower Published on 2003-11-5 18:04 Talking about microcontrollers ← Back to the page   

;-------96-key demonstration program-------------------------
;This is an application example in a reply question, which has been "verified" by software simulation
; This is just a "miniature" of key scanning technology, and there are too many methods.
;There are "ugly places", and experts are welcome to criticize and advise.
;HotPower will accept it humbly, resolutely correct it and make a new start.
;Purpose of publication: To strengthen the guerrillas in 21IC.
;----------------------------------------------------
;Due to the problem of 2051 resources, this program only takes the two events of the press and release keys of the multi-tasking keyboard
; Abolish the long press key event (press the key for a period of time before activation)
; Abolish the long release key event (release the key for a period of time before activation)
; Abolish the double-click key event
; Abolish any combination of key events
;----------Constant definition------------------------------
TIME208US  EQU -208;20mS/96=208uS
TIME50MS   EQU -5000;50000uS
;KEYCOUNT   EQU   1; Number of keyboard keys (used in software simulation)
;------------------------------------------------
KEYCOUNT   EQU   96; Number of keyboard keys (actual application)

;----------RAM address definition----------------------------
;--------96-key key status flag bit array Bits[12*8 bits]--------
KEYBUFF1   DATA  08H;08H~13H (12 bytes 96 bits) correspond to 96 keys
;--------96-key key jump flag bit array Bits[12*8 bits]--------
KEYBUFF2   DATA  14H;14H~1FH (12 bytes 96 bits) correspond to 96 keys
;------------------------------------------------
KEYNUM     DATA  30H;
HotPower_55H      DATA   6EH
HotPower_AAH      DATA   6FH
;---------------------------------------
SP_MIN       DATA HotPower_AAH
;-------Main program starts----------------------
   ORG   0000H
START:
   LJMP  MAINSTART;Main program starts
   ORG   0003H
;-------Power-off protection interrupt INT0 service program--------
INT0_INTADDR:
   RETI
   ORG   000BH
;-------Timer T0 interrupt service program------------
;Work in 8-bit automatic loading mode, interrupt once every 208uS T0_INTADDR 
:
   LJMP  T0INTPROC;Timer T0 interrupt service programRETI
   ORG 0013H ;-------External interrupt INT1 service program------------ INT1_INTADDR: RETI
   ORG  001BH ;-------Timer T1 interrupt service program------------ T1_INTADDR: LJMP  T1INTPROC;Timer T1 interrupt service programRETI ; ORG  0023H ;-------Serial interrupt service program---------------- ;  SINT_INTADDR: ;  RETI ;------------------------------------------- ;  ORG  002BH ;-------Timer T2 interrupt service program------------ ;  LJMP  T2INTPROC;Execute interrupt service program ;  RETI ;-------Execute keyboard command---------------------- ;This program uses the scattered transfer recovery technology (pointer function) ; its biggest advantage is that the subroutine at the scattered transfer location can be used by it (function) ; it is much more "guerrilla" than the JMP @A+DPTR instruction, and is much more flexible and hidden ; it is "worse" than JMP @A+DPTR in dealing with "disassembly" ; HotPower would never use JMP @A+DPTR KEYPROC: ;Entrance:  DPTR scattered transfer address table ;  ACC scattered transfer number CJNE  A,#KEYCOUNT,$+3 JNC  KEYPROC_EXIT; illegal keys (96~255) prevent program flying, no scattered transfer RL  A; *2; address requires 2 bytes (like ARM big-endian mode) ADD  A,DPL MOV  DPL,A CLR  A ADDC  A,DPH MOV  DPH,A MOV  A,#01H; low 8 bits MOVC  A,@A+DPTR; take the low 8 bits address PUSH  ACC; push the low 8 bits address CLR  of event processing A; MOVC  A, @A+DPTR; Get the high 8-bit address PUSH  ACC; Push the high 8-bit address of the event processing KEYPROC_EXIT: RET; Execute the keyboard command (JMP @A+DPTR) 


   
    


   
   
   


  

   

  
  








     
   
    
     
    
    
    
   
    
    
   
       
        
   
       

   
;-------Key press event processing address table--------------------
KEYJMPPROCTAB:
   DW    KEYPROC0;0 key press
   DW    KEYPROC1
   DW    KEYPROC2
;............................
   DW    KEYPROC95;95 key press
;-------Key release event processing address table--------------------
KEYJMPPROCTABX:
   DW    KEYPROC0X;0 key release
   DW    KEYPROC1X
   DW    KEYPROC2X
;............................
   DW    KEYPROC95X;95 key release
MAINSTART:
;----------P0 port initialization------------------
   MOV   P0,#11111111B
;-------P1 port initialization------------------
   MOV   P1,#11111111B
;-------P2 port initialization------------------
   MOV   P2,#11111111B
;-------P3 port initialization------------------
   MOV   P3,#11111111B
;--------------------------------
   MOV   IE,#00000000B;EA=0,ES=ET2=ET1=EX1=ET0=EX0=0
   MOV   SP,#SP_MIN;
         MOV   PSW,#00000000B;RS1RS0=00,R0~R7=00H~07H
   MOV   A,#LOW(MAINNEXT)
   PUSH  ACC
   MOV   A,#HIGH(MAINNEXT)
   PUSH  ACC
   RETI
MAINPROC:
   LCALL MAININIT;System initialization
       MOV   IE,#10001010B;Open interrupt
;-------Main loop-------------------------------
MAINLOOP:
   ORL   PCON,#10001101B;Standby
   SJMP  MAINLOOP;Dead loop
MAINNEXT:
   MOV   A,#LOW(MAINPROC)
   PUSH  ACC
   MOV   A,#HIGH(MAINPROC)
   PUSH  ACC
   RETI
;-------Main program initialization------------------------
MAININIT:
;-------Interface initialization--------------------------
;-------Memory initialization-------------------------
   MOV   A,HotPower_55H
   XRL   A,HotPower_AAH
   CPL   A
   JZ    MAININITNEXT;Memory is not destroyed
   MOV   HotPower_55H,#055H
   MOV   HotPower_AAH,#0AAH
   LCALL SYSTEMINIT;System initialization
MAININITNEXT:
;-------Run initialization---------------
   LCALL SYSTEMSETUP;System setup
   RET
SYSTEMINIT:
   LCALL KEYBUFFINIT
   RET
SYSTEMSETUP:
;-------System main frequency 12MHz---------------------------------
;    MOV   IP,#00100001B;Interrupt priority EX0>ET2>ET0>EX1>ES
    MOV   TMOD,#00010010B;T1=MODE1(16-bit timer),T0=MODE2(8-bit timer)
   MOV   TCON,#01010101B;Start timer TR1EQUTR0EQU1,IT1EQUIT0EQU1
;------------------------------------------------------
   MOV   TL0,#TIME208US;Set timer 0 time constant
   MOV   TH0,#TIME208US;Set timer 0 time constant
;------------------------------------------------------
;    MOV   TL1,#LOW(TIMEXMS);Set timer 1 time constant
;    MOV   TH1,#HIGH(TIMEXMS)
;-------
KEYBUFFINIT:
   MOV   KEYNUM,#00H
   MOV   R0,#KEYBUFF1
KEYBUFFINITLOOP:
   MOV   @R0,#00H
   INC   R0
   CJNE  R0,#KEYBUFF2+12,KEYBUFFINITLOOP
   RET
;---------------------------------------------
INKEY:
;Every time T0 is interrupted, a key "scan" will be performed
   LCALL TESTKEY;Keyboard test (no scanning but description)
;-------Keyboard soft simulation test point-----------------
;Here   A=0 No key is pressed, A<>0 has a key pressed
; if debugging n keys, KEYCOUNT needs to be set to n. (KEYCOUNT=1~96)
;----------------------------------------
   JNZ   INKEY1; A key is pressed
INKEY0:
;-------No key is pressed------------------------
   LCALL GETKEYBIT; Get key status
   JZ    INKEY01; The key status has not changed
       LCALL CLRKEYBIT; Set the key release flag
   LCALL SETKEYBITK; Set the jump flag (to prevent key release jitter)
   RET
INKEY01:
   LCALL GETKEYBITK; Get the key jump flag
   JZ    INKEY02; The key has not jumped (to prevent double event processing)
   LCALL CLRKEYBITX; Set the reentry flag
       MOV   A,KEYNUM; Get the key number
       MOV   DPTR,#KEYJMPPROCTABX; Keyboard key release event processing table
   LCALL KEYPROC; Execute keyboard key release event processing
INKEY02:
   RET
INKEY1:
;-------A key is pressed------------------------
   LCALL GETKEYBIT;Get key status
   JNZ   INKEY11;The key status has not changed (to prevent double event processing)
       LCALL SETKEYBIT;Set key pressed flag
   LCALL SETKEYBITK;Set transition flag (to prevent key pressed jitter)
   RET
INKEY11:
   LCALL GETKEYBITK;Get key transition flag
   JZ    INKEY12;The key has not transitioned
   LCALL CLRKEYBITX;Set reentry flag
       MOV   A,KEYNUM;Get key number
       MOV   DPTR,#KEYJMPPROCTAB;Keyboard key pressed event processing table
   LCALL KEYPROC;Execute keyboard key pressed event processing
INKEY12:
   RET
GETKEYBITK:
   MOV   A,R0
   ADD   A,#12
   MOV   R0,A
   SJMP  GETKEYBITX
GETKEYBIT:
   LCALL GETKEYBITADDR
   LCALL GETKEYBITVAL
GETKEYBITX:
   MOV   A,@R0
       ANL   A,B
   RET
SETKEYBITK:
   MOV   A,R0
   ADD   A,#12
   MOV   R0,A
   SJMP  SETKEYBITX
SETKEYBIT:
   LCALL GETKEYBITADDR
   LCALL GETKEYBITVAL
SETKEYBITX:
   MOV  A,@R0
       ORL   A,B
   MOV   @R0,A
   RET
CLRKEYBITK:
   MOV   A,R0
   ADD   A,#12
   MOV   R0,A
   SJMP  CLRKEYBITX
CLRKEYBIT:
   LCALL GETKEYBITADDR
   LCALL GETKEYBITVAL
CLRKEYBITX:
   MOV   A,@R0
   XRL   B,#0FFH; Negate B
       ANL   A,B
   XRL   B,#0FFH; restore B
   MOV   @R0,A
   RET
;------------------------------- -------
;CPLKEYBITK:
;    MOV   A,R0
;    ADD   A,#12
;    MOV   R0,A
;    SJMP  CPLKEYBITX
;CPLKEYBIT:
;    LCALL GETKEYBITADDR
;    LCALL GETKEYBITVAL
;CPLKEYBITX:
;    MOV   A,@R0
;        XRL   A ,B
;    MOV   @R0,A
;    RET
;---------------------------------------------
GETKEYBITVAL:
   MOV   A ,KEYNUM
   ANL   A,#07H
   ADD   A,#GETKEYBITTAB-GETKEYBITTABOFF MOVC 
   A  ,@A+PC
GETKEYBITTABOFF:
   MOV   B,A
   RET GETKEYBITTAB
:
   DB    00000001B
   DB    00000010B
   DB    00000100B
   DB    00010000B
   DB    00100000B
   DB    01000000B
   DB    10000000B RET ;-- -------------------------------------------- GETKEYBITADDR: MOV  A,KEYNUM ANL  A,#01111000B RR  A RR  A RR  A ADD  A,#KEYBUFF1 MOV  R0,A RET ;-------Key test subroutine----------------- --------- TESTKEY: ;Key number KEYNUM=000 0000B~101 1111B(0~95) ;Entry  None ;Exit  ACC==0 No key pressed (key number KEYNUM) ;  ACC<>0 A key is pressed (key number KEYNUM) MOV  A,KEYNUM; get key number ANL  A,#0FH; get line number (lower 4 bits of key number) ANL  P3,#0F0H; clear line signal ORL  P3,A; send line scan signal DCBA; P3.3~P3.0 MOV  A,KEYNUM; get the key number ANL  A,#01110000B; get the column number (the upper 3 bits of the key number) SWAP  A; change to the lower 3 bits ADD 
     
   


    
    
     
     
     
    
    
   



 
 
     
    
    
    
    
    
    
   
    A,#TESTKEYTAB-TESTKEYTABOFF; get the table address
       MOVC  A,@A+PC; get the table value
TESTKEYTABOFF:
   JZ    TESTKEYEXIT; 6,7 illegal columns, it is considered that no key is pressed
   PUSH  B; protect the scene
   MOV   B,A; temporarily store
   ANL   A,P1; receive column values ​​P1.7~P1.2, if a key is pressed, it is 0
   XRL   A,B; if a key is pressed, it is not 0
   POP   B; restore the scene
TESTKEYEXIT:
   RET
TESTKEYTAB:
   DB    00000100B; 0 column
   DB    000010000B; 1 column
   DB    00010000B; 2 column
   DB    00100000B; 3 column
   DB    01000000B; 4 column
   DB    10000000B; 5 column
   DB    00000000B; 6 column illegal
   DB    00000000B;7 columns are illegal
;-------Timer T0 interrupt service program--------------------
;Each key is scanned once every 20ms, and the key pressing or releasing is automatically debounced
;This is an atypical example of a large-scale (96-key) keyboard guerrilla war
;Features:
;1. No key scanning is required. (The order of T0 interrupt is the key scan number)
;2. No key debounce is required. (The key is automatically debounced after 96 T0 interrupts)
;3. Separation of key pressing and releasing events (scattered transfer recovery technology)
;4. "Parallel processing" of user events (mS level time sharing)
T0INTPROC:
   PUSH  PSW
   PUSH  ACC
   PUSH  B
   PUSH  DPL
   PUSH  DPH
T0INTPROC_START:
   LCALL INKEY;Key scan and execute key pressing and releasing event processing
   INC   KEYNUM;Prepare for the next key number (T0 interrupt count)
   MOV   A,KEYNUM
   CJNE  A,#KEYCOUNT,T0INTPROC_EXIT
   MOV   KEYNUM,#00H; Start the next round of key scan
T0INTPROC_EXIT:
   POP   DPH
   POP   DPL
   POP   B
   POP   ACC
   POP   PSW
   RETI
;------Timer T1 interrupt service program------------
T1INTPROC:
   RETI
;-------0 key press event processing---------------------
KEYPROC0:
;Add user key press event
   hereRET
;-------1 key press event processing---------------------
KEYPROC1:
;Add user key press event
   hereRET
;-------2 key press event processing---------------------
KEYPROC2:
;Add user key press event
   hereRET
;-------95 key press event processing---------------------
KEYPROC95:
;Add user key press event
   hereRET
;-------0 key release event processing---------------------
KEYPROC0X:
;Add user key release event hereRET
   ;
-------1 key release event processing---------------------
KEYPROC1X:
;Add user key release event here
   RET
;-------2 key release event processing---------------------
KEYPROC2X:
;Add user key release event here
   RET
;-------95 key release event processing---------------------
KEYPROC95X:
;Add user key release event here
   RET
;-------All programs end--------------------------------------
   END

Key scan driver
 
 
//Key scan driver

unsigned char key,key_h,kpush;
unsigned int key_l;

//Buttons connected to p1.0, p1.1, p1.2

void int_t0(void) interrupt 1 {
 unsigned char dd,i;
 TL0=TL0+30;TH0=0xfb; //800
 
 if ((P1&0x7)==0x7) {
 if ((key_l>30)&&(key_l<800)&&(key_h>30)) {  //Release the key. If the previous key press time is less than 1 second, read the key value
  key=kpush;
 }
 if ((++key_h)>200) key_h=200;
 key_l=0;
 if (key>=0x80) key=0;       //If the previous key press was long pressed for 1 second, clear the key value
 } else {
 kpush=P1&0x7;
 key_l++;
 if ((key_l>800)&&(key_h>30)) {     //If the key press exceeds 1 second, add 0x80 to the key value to mark the long press
  key=kpush|0x80;
  key_h=0;
  key_l=0;
 }
 }
}
void main(void) {
 TMOD=0x1;TR0=1;ET0=1;EA=1;
 while (1) {
 while (!key) {}
 switch (key) {
 case 1:break;
 case 2:break;
 }
 }
}