* Written by Roger Schaefer * * DS1202 Serial Timekeeping Chip * DALLAS SEMICONDUCTOR * * The following subroutines read and write to a * DS1202 or the newer DS1302 real time chip. * * * CLK_INIT EQU * BCLR RTClkPort RST ;be sure RST low BSET RTClkDDR RST BCLR RTClkPort SCLK ;clock low BSET RTClkDDR SCLK BCLR RTClkPort I_O ;i/o line low BSET RTClkDDR I_O RTS ********************************* Get_Seconds: ;return in A in packed BCD ldaa #0 ;seconds jsr READ_CLK rts Get_Minutes: ;return in A in packed BCD ldaa #1 ;minutes jsr READ_CLK rts Get_Hour: ;return in A in packed BCD ldaa #2 ;hour jsr READ_CLK rts Get_am_pm: ;return 0 if am; $FF if pm ldaa #2 ;hour jsr READ_CLK anda #%00100000 beq am ldaa #$ff am rts Get_Date: ;return in A in packed BCD ldaa #3 ;date jsr READ_CLK rts Get_Day: ;return in A in packed BCD ldaa #5 ;weekday jsr READ_CLK rts Get_Month: ;return in A in packed BCD ldaa #4 ;month jsr READ_CLK rts Get_Year: ;return in A in packed BCD ldaa #6 ;year jsr READ_CLK rts * * Read a register from the DS1202 clock * Enter with the register number in A * Return with the data in A * READ_CLK EQU * ANDA #$7 ;lower 3 bits only LSLA ORAA #%10000001 ;read command RD_CK0 PSHX LDX #REGBS BSR CLK_INIT BSET RTClkPort,X RST ;enable chip BSR WT_CK1 BCLR RTClkDDR,X I_O ;now input LDAB #8 RD_CK4 BCLR RTClkPort,X SCLK CLC BRCLR RTClkPort,X, I_O, RD_CK5 SEC RD_CK5 RORA BSET RTClkPort,X SCLK DECB BNE RD_CK4 BCLR RTClkPort,X RST PULX RTS * WT_CK1 LDAB #8 RD_CK1 BCLR RTClkPort,X SCLK LSRA BCS RD_CK2 BCLR RTClkPort,X I_O BRA RD_CK3 RD_CK2 BSET RTClkPort,X I_O RD_CK3 BSET RTClkPort,X SCLK DECB BNE RD_CK1 RTS * ISPDIGIT EQU * PSHB ANDB #$F CMPB #9 BHI ISPD_BAD PULB PSHB LSRB LSRB LSRB LSRB CMPB #9 BHI ISPD_BAD PULB SEC ;Set C if OK RTS * ISPD_BAD EQU * LDX #MSG9 JSR OUTSTRG PULB CLC ;Clear C if not OK RTS * SET_MINUTE EQU * JSR WSKIP JSR BUFFARG TST COUNT BEQ SET_M9 ;go if no argument LDAB SHFTREG+1 BSR ISPDIGIT BCC SET_M9 CLRA CLRB ;Set seconds to 0 BSR WRITE_CLK LDAB SHFTREG+1 LDAA #1 ;Reg Addr MIN BSR WRITE_CLK SET_M9 JSR SHOW_TIME RTS * SET_HOUR EQU * JSR WSKIP JSR BUFFARG TST COUNT BEQ SET_H9 ;go if no argument LDAB SHFTREG+1 BSR ISPDIGIT BCC SET_H9 LDAA #2 ;Reg Addr HR BSR WRITE_CLK SET_H9 JSR SHOW_TIME RTS * SET_DAY EQU * JSR WSKIP JSR BUFFARG TST COUNT BEQ SET_D9 ;go if no argument LDAB SHFTREG+1 BSR ISPDIGIT BCC SET_D9 LDAA #3 ;Reg Addr DATE BSR WRITE_CLK SET_D9 JSR SHOW_DATE RTS * SET_MONTH EQU * JSR WSKIP JSR BUFFARG TST COUNT BEQ SET_MO9 ;go if no argument LDAB SHFTREG+1 JSR ISPDIGIT BCC SET_MO9 LDAA #4 ;Reg Addr MONTH BSR WRITE_CLK SET_MO9 JSR SHOW_DATE RTS * SET_YEAR EQU * JSR WSKIP JSR BUFFARG TST COUNT BEQ SET_Y9 ;go if no argument LDAB SHFTREG+1 JSR ISPDIGIT BCC SET_Y9 LDAA #6 ;Reg Addr YEAR BSR WRITE_CLK SET_Y9 JSR SHOW_DATE RTS * * * Write a register to the DS1202 clock * Enter with the DS1202 register in A and * the data to write in B * WRITE_CLK EQU * PSHA PSHB LDAA #7 ;Control register LDAB #0 ;OK to write BSR WT_CK0 PULB PULA ;get data back BSR WT_CK0 WT_CK3 LDAA #7 LDAB #$80 ;Set WP WT_CK0 ANDA #$7 ;lower 3 bits only LSLA ORAA #%10000000 ;write command WT_CK2 PSHX PSHB LDX #REGBS JSR CLK_INIT BSET RTClkPort,X RST ;enable chip JSR WT_CK1 PULB TBA JSR WT_CK1 ; BCLR RTClkDDR,X %00011000 BCLR RTClkPort,X RST PULX RTS * * * Read a ram location from the DS1202 chip * Enter with the address in A * Return with the data in A * READ_RAM: ANDA #$3F LSLA ORAA #%11000001 ;read command JMP RD_CK0 ;reuse code * * Enter with the DS1202 register in A and * the data to write in B * WRITE_RAM: PSHA PSHB LDAA #7 ;Control register LDAB #0 ;OK to write BSR WT_CK0 PULB PULA ;get data back ANDA #$3F LSLA ORAA #%11000000 ;write command BSR WT_CK2 BRA WT_CK3 ;Set WP & Goodbye ************************************************** END