;------------------------------------------------------------------------ ; ; TL_NL.ASM ; ; Author: San Bergmans ; www.sbprojects.com ; ; Created for the 6802 Nano Computer at 15-11-1993 ; ; This program demonstrates the traffic lights on a normal intersection ; The lights on the main road show green simultaneously, while the ; lights from the side road show green in turn. ; ;------------------------------------------------------------------------ .CR 6800 Select cross overlay .OR $F000 .TF TL_NL.HEX,INT Specify target file ;------------------------------------------------------------------------ ; Declaration of constants ;------------------------------------------------------------------------ TABLE_PNTR .EQ $00,01 Pointer in state table LIGHTS_A1 .EQ $02 Status for lights on road A LIGHTS_A2 .EQ $03 LIGHTS_B1 .EQ $04 Status for lights on road B LIGHTS_B2 .EQ $05 PIA_A .EQ $0080 Pia data register A PIA_B .EQ $0081 Pia data register B CON_A .EQ $0082 Pia control register A CON_B .EQ $0083 Pia control register B DELAY .EQ 12500 Delay counter for approx. 100ms. ;------------------------------------------------------------------------ ; Reset and initialisation ;------------------------------------------------------------------------ RESET LDS #$007F Reset stack pointer LDAA #%0000.0100 Initialise PIA ports STAA CON_A STAA CON_B LDAA #%0011.1111 b0..b5 are outputs b6+b7 are STAA PIA_A inputs for both PIA ports STAA PIA_B CLRB STAB CON_A STAB CON_B STAA PIA_A STAA PIA_B LDAA #%0000.0100 Select data registers again STAA CON_A STAA CON_B LDX #STATE_TABLE Load start address of STX TABLE_PNTR state table ;------------------------------------------------------------------------ ; Main program loop ;------------------------------------------------------------------------ MAIN LDX TABLE_PNTR Load state table pointer LDAB 0,X Get delay time from table BNE .NOT_END Not the end of the table yet! LDAA 1,X Restart the table (take reload STAA TABLE_PNTR value from the end of the table) LDAA 2,X STAA TABLE_PNTR+1 LDX TABLE_PNTR LDAB 0,X Get new delay time again .NOT_END INX Read light patterns for Road A LDAA 0,X STAA LIGHTS_A1 Keep light pattern in RAM INX LDAA 0,X STAA LIGHTS_A2 INX Read light patterns for Road B LDAA 0,X STAA LIGHTS_B1 Keep light pattern in RAM INX LDAA 0,X STAA LIGHTS_B2 INX Save the incremented pointer STX TABLE_PNTR BSR WAIT Show this pattern for a while BRA MAIN Repeat the main loop for ever ;------------------------------------------------------------------------ ; Wait until the delay is over (includes flashing of lights). ;------------------------------------------------------------------------ WAIT BITB #%0000.0100 What is the current flash state? BEQ .LIGHTS_ON State 1! Lights are always on! LDAA LIGHTS_A2 Copy 2nd status to the outputs STAA PIA_A LDAA LIGHTS_B2 STAA PIA_B BRA .DEC_WAIT .LIGHTS_ON LDAA LIGHTS_A1 Copy 1st status to the outputs STAA PIA_A LDAA LIGHTS_B1 STAA PIA_B .DEC_WAIT BSR DELAY_100MS Delay about 100 milli seconds DECB Decrement total delay counter BNE WAIT Not 0 yet! Repeat delay loop RTS ;------------------------------------------------------------------------ ; Wait 0.1s routine ;------------------------------------------------------------------------ DELAY_100MS LDX #DELAY Set delay counter and count down .LOOP DEX to 0 BNE .LOOP Not 0 yet! RTS ;------------------------------------------------------------------------ ; State table ; ; 5 Bytes per record ; Byte 1: Time of this state (x 0.1s) ; Byte 2: b7 = not used ; b6 = not used ; b5 = red light A1 (0=light on) ; b4 = yellow light A1 ; b3 = green licht A1 ; b2 = red light A0 ; b1 = yellow light A0 ; b0 = green light A0 ; Byte 3: same as byte 1, now for the off state during flashing ; Byte 4: Same as Byte 2, but this time for road B ; Byte 5: Same is Byte 3, but this time for road B ; ; End of table if first record byte = 0. Then the next 2 bytes indicate ; the loop address in the state table. ;------------------------------------------------------------------------ STATE_TABLE ; show during 10 seconds all yellow flashing lights .DA #100 100x 0.1 seconds .DA #%00.101.101 Road A Yellow flashing .DA #%00.111.111 .DA #%00.101.101 Road B Yellow flashing .DA #%00.111.111 ; show 5 seconds all red lights .DA #50 50x 0.1 seconds .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.011 Road B all Red .DA #%00.011.011 .LOOP ; road A green, road B red, 8 seconds .DA #80 .DA #%00.110.110 Road A all Green .DA #%00.110.110 .DA #%00.011.011 Road B all Red .DA #%00.011.011 ; road A yellow, road B red, 2.5 seconds .DA #25 .DA #%00.101.101 Road A all Yellow .DA #%00.101.101 .DA #%00.011.011 Road B all Red .DA #%00.011.011 ; all roads red for 1 second .DA #10 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.011 Road B all Red .DA #%00.011.011 ; road A red, road B0 green, road B1 red, 8 seconds .DA #80 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.110 Road B0 Green, B1 Red .DA #%00.011.110 ; road A red, road B0 yellow, road B1 red, 2.5 seconds .DA #25 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.101 Road B0 Yellow, B1 Red .DA #%00.011.101 ; all roads red for 1 second .DA #10 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.011 Road B all Red .DA #%00.011.011 ; road A red, road B1 green, road B0 red, 8 seconds .DA #80 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.110.011 Road B0 Red, B1 Green .DA #%00.110.011 ; road A red, road B1 yellow, weg B0 red, 2.5 seconds .DA #25 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.101.011 Road B0 Red, B1 Yellow .DA #%00.101.011 ; all roads red for 1 second .DA #10 .DA #%00.011.011 Road A all Red .DA #%00.011.011 .DA #%00.011.011 Road B all Red .DA #%00.011.011 ; end of table and next address in table to contionue .DA #%00.000.000,.LOOP ;------------------------------------------------------------------------ ; Interrupt and reset vectors ;------------------------------------------------------------------------ .NO $FFF8,$FF .DA RESET IRQ (not used) .DA RESET SWI (not used) .DA RESET NMI (not used) .DA RESET Reset .LI OFF