;************************** ADB.EQU Header - Sets up EQUates ************* ;*** TESTING *** BITS USED IN TESTING FOR I/O ; *** BOOLEANS USED TO SELECT PART BEING USED ; Only One Part May Be selected at a time C54 equ FALSE ;TRUE C55 equ FALSE C56 equ TRUE ;FALSE C57 equ FALSE LED equ 00h ; *** AN LED ON LINE RB0 INDICATES SWITCH PRESSED Switch equ 01h ; *** 'Switch' USED FOR A SWITCH ON LINE RB1 AND ; *** AS A FLAG IN FLAGS2 FOR DEBOUNCING SHIFT equ 38h BANG equ 12h DEBOUNC equ 08h ; *** # OF TIMES TO LOOP TO ALLOW DEBOUNCE OF SWITCH ; *** BIT ASSIGNMENTS FOR I/O LINES & TRI-STATING ADB equ 00h ; Line used for ADB - pin XX (16C54) RA1 equ 01h ; May be used as a Clock line TO another PIC RA2 equ 02h ; May be used as a Clock line FROM another PIC RA3 equ 03h ; May be used as a Data line between two PICs TRI_IN equ 01h ; tri-state for ADB pin as input TRI_OUT equ 00h ; tri-state for ADB pin as output ;*** MISC. CONSTANTS BYTE equ 08h ; Receive 8 bits in Command; count from 8 to 0 DEF_ADD equ 02h ; default device address to start with (kybd) DEF_HND equ 03h ; default Handler Id. to start with (std. kybd) OFFSET equ 08h ; offset to RAM address of the array of ADB ; Data storage registers ;*** COMMAND MASKS: MASK BITS FROM COMMAND REGISTER FOR: DEVMASK equ 0Fh ; lower nibble holds Command (Talk, etc.) & Reg. # ADDRMSK equ 0F0h ; upper nibble holds the Device Address Number CMDNIBL equ 0Fh ; Command nibble from the address CMDTYPE equ 0Ch ; Upper 2 Command bits indicate Talk, Listen, etc. REGMASK equ 03h ; Data Register Number bits from Command Nibble FSRMASK equ 1Fh ; FSR bits from the Command Nibble for RAM Address ;*** DATA COMMAND MASKS: MASK DATA REGISTER 3a FOR: LOW_NBL equ 0Fh ; Lower nibble from the 1st Data byte HI_NIBL equ 0F0h ; Upper nibble from the 1st Data byte ;*** CONSTANTS FOR MASKING OUT COMMAND NIBBLES (C_ indicates Command) ; used to XOR if this is a: C_TALK equ 0Ch ; Talk Command C_LISTN equ 08h ; Listen Command C_RESET equ 00h ; Reset Command C_FLUSH equ 01h ; Flush Command C_RES_1 equ 04h ; Reserved Command 1 C_RES_2 equ 02h ; Reserved Command 2 C_RES_3 equ 03h ; Reserved Command 3 ;*** DATA HANDLER ID MASKS: MASK DATA REGISTER 3b FOR: SELFTST equ 0FFh ; Self-Test mode LISTEN1 equ 0h ; unconditional address change LISTEN2 equ 0FEh ; address change if no collision detected DEV_ACT equ 0FDh ; address change if device activator is depressed ;*** BITS USED IN THE UPPER NIBBLE OF REGISTER 3a FOR SPECIAL ADB STATUS BITS Resrvd3 equ 04h ; reserved (Always 0) Srq_Bit equ 05h ; determines if Host will accept Service Requests ExpEvnt equ 06h ; indicates an Exceptional Event should take place Always0 equ 07h ; always set to 0 ;*** ADB FLAG BITS IN THE "FLAGS1" REGISTER (F1 indicates 1st Flags register) F1Attn equ 00h ; set to know if 2nd Task taking place during Attn F1Reg3 equ 01h ; Register 3 is being addressed F1Talk equ 02h ; indicates to Tlt routine this is a Talk Command F1Stop equ 03h ; set to indicate the Data Stop Bit is being sent F1Lstn equ 04h ; indicates to Tlt routine this is a Listen Command F1Sent1 equ 05h ; 1st byte of Data Register has been sent F1Rcvd1 equ 06h ; 1st byte of Data Register has been received F1Cllsn equ 07h ; set to indicate that a collision occurred ;*** FLAG BITS IN THE "FLAGS2" REGISTER (F2 indicates 2nd Flags register) F2Srq equ 00h ; indicate that Srq should be issued ; 01h Switch, defined above for PORT_B, also used as a Flag F2DActv equ 02h ; change address if Device Activator is Depressed F2STest equ 03h ; set to indicate a device Self Test is to be performed F2SFail equ 04h ; set to indicate that the Device Self-Test Failed F2DRcvd equ 05h ; set when data is received for 2nd Application Task F2DSend equ 06h ; set to indicate to Talk that Data needs to be sent F2DMore equ 07h ; set in 2nd Task to indicate Data remains to be sent ;*** TIMING DEFINITIONS ; These values currently used for clock at 4Mhz: PrSclr1 equ .4 ; this is used when the RTCC is being prescaled PrSclr2 equ .1 ; this is used when the RTCC is not prescaled ATT_MIN equ .776/PrSclr1 ; Attn lower limit: 800 - 3% tolerance = 776 usecs ATT_MAX equ .824/PrSclr1 ; Attn upper limit: 800 + 3% tolerance = 824 usecs TSK2MIN equ .500/PrSclr1 ; time given to 2nd Task during Attn Signal TSK2MAX equ .900/PrSclr1 ; time given to 2nd Task after Data Sent/Received SYNC equ .72/PrSclr2 ; Sync with extra tolerance after Attn is detected BIT_TST equ .50/PrSclr2 ; if time is < 50 = 1 bit, & > 50 = 0 bit MAX_BIT equ .72/PrSclr2 ; Maximum time line can be low for a bit BITCELL equ .104/PrSclr2 ; Maximum time for a bit cell = 104 usecs TLT_MIN equ .140/PrSclr2 ; Stop to Start minimum time = 140 usecs TLT_MAX equ .250/PrSclr2 ; Stop to Start maximum time = 260 usecs TLT_MID equ .180/PrSclr2 ; Stop to Start median time = 208 usecs SRQ_MAX equ .296/PrSclr1 ; amount of time to hold for a Service ReQuest ; NOTE: for RTCC timing of sending bits, some extra time is allowed for ; instruction cycles between the end of the bit and the start of the next bit LOW1BIT equ .22/PrSclr2 ; low time for a 1 bit HI_1BIT equ .50/PrSclr2 ; hi time for a 1 bit LOW0BIT equ .56/PrSclr2 ; low time for a 0 bit HI_0BIT equ .20/PrSclr2 ; hi time for a 0 bit ;*** ADB DATA REGISTERS - 2 BYES FOR EACH OF REGISTERS 0, 1, 2, and 3 ADB_REG ORG 08h ; ORIGIN FOR ADB DATA REGISTERS Reg0a RES 01h ; 8 Reg0b RES 01h ; 9 Reg1a RES 01h ; A Reg1b RES 01h ; B Reg2a RES 01h ; C Reg2b RES 01h ; D Reg3a RES 01h ; E Reg3b RES 01h ; F ;*** VARIABLE REGISTERS FOR STORAGE, FLAGS, THE TIME VARIABLE, THE COUNTER, ; & RANDOM VALUES STORAGE ORG 10h ; ORIGIN FOR MISC. DATA VARIABLES TmpReg1 RES 01h ; 10 - temporary registers where Data is sent from & TmpReg2 RES 01h ; 11 - received; NOTE: THESE 2 MUST BE IN THIS ORDER RegNum RES 01h ; 12 - holds current ADB Data Reg.# - NOT a RAM address RAMaddr RES 01h ; 13 - holds RAM address of ADB Data Reg.# Flags1 RES 01h ; 14 - two Flags registers used by ADB & 2nd Flags2 RES 01h ; 15 - Application Task CmdByte RES 01h ; 16 - holds the Command Byte BitCntr RES 01h ; 17 - counts down when sending or receiving bits Random RES 01h ; 18 - stores Random Address sent in Talk routine TimeVar RES 01h ; 19 - used with RTCC for all ADB timing Tsk2Var RES 01h ; 1A - used with RTCC for timing during 2nd Task ;*** REGISTERS STILL AVAILABLE TmpCtr1 RES 01h ; 1B TmpFlg1 RES 01h ; 1C TmpFlg2 RES 01h ; 1C TmpFlg3 RES 01h ; 1D TmpFlg4 RES 01h ; 1E PROGRAM ORG 00h ; origin for program