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ameziti |
;KCPSM3 Program - Real Time Clock with UART communication.
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;
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;Ken Chapman - Xilinx Ltd - October 2003
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;
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;
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;Port definitions
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;
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CONSTANT UART_status_port, 00 ;UART status input
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CONSTANT tx_half_full, 01 ; Transmitter half full - bit0
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CONSTANT tx_full, 02 ; FIFO full - bit1
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CONSTANT rx_half_full, 04 ; Receiver half full - bit2
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CONSTANT rx_full, 08 ; FIFO full - bit3
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CONSTANT rx_data_present, 10 ; data present - bit4
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;
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CONSTANT UART_read_port, 01 ;UART Rx data input
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;
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CONSTANT UART_write_port, 01 ;UART Tx data output
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;
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CONSTANT alarm_port, 00 ;Alarm output
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CONSTANT alarm_control, 01 ; bit0
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;
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;Special Register usage
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;
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NAMEREG sF, UART_data ;used to pass data to and from the UART
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;
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NAMEREG sE, store_pointer ;used to pass location of data in scratch pad memory
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;
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;Two registers to form a 16-bit counter used to count
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;interrupt pulses generated at 1us intervals.
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;
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NAMEREG sD, int_counter_lsb ;lower 8-bits
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NAMEREG sC, int_counter_msb ;upper 8-bits
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;
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;
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;Scratch Pad Memory Locations
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;
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;
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CONSTANT us_time_stamp_lsb, 00 ;16-bit micro-second time stamp
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CONSTANT us_time_stamp_msb, 01
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;
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CONSTANT us_time_lsb, 02 ;16-bit micro-second real time value
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CONSTANT us_time_msb, 03
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;
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CONSTANT ms_time_lsb, 04 ;16-bit milli-second real time value
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CONSTANT ms_time_msb, 05
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;
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CONSTANT real_time_hours, 06 ;Current clock time
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CONSTANT real_time_minutes, 07
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CONSTANT real_time_seconds, 08
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;
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CONSTANT alarm_time_hours, 09 ;Alarm time
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CONSTANT alarm_time_minutes, 0A
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CONSTANT alarm_time_seconds, 0B
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;
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CONSTANT alarm_status, 0C ;Alarm status
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CONSTANT alarm_active, 01 ; bit0 - Alarm is active
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CONSTANT alarm_armed, 02 ; bit1 - Alarm is armed
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;
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CONSTANT time_preserve0, 10 ;storage for protection of registers
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CONSTANT time_preserve1, 11 ;used by the real time clock routine.
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CONSTANT time_preserve2, 12
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CONSTANT time_preserve3, 13
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CONSTANT time_preserve4, 14
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CONSTANT time_preserve5, 15
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;
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;UART character strings will be stored in scratch pad memory ending in carriage return.
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;A string can be up to 16 characters with the start location defined by this constant.
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;
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CONSTANT string_start, 20
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;
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;
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;Initialise the system
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;
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;
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cold_start: LOAD s0, 00 ;clear all time values
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STORE s0, us_time_stamp_lsb
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STORE s0, us_time_stamp_msb
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STORE s0, us_time_lsb
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STORE s0, us_time_msb
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STORE s0, ms_time_lsb
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STORE s0, ms_time_msb
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STORE s0, real_time_hours
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STORE s0, real_time_minutes
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STORE s0, real_time_seconds
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STORE s0, alarm_time_hours
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STORE s0, alarm_time_minutes
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STORE s0, alarm_time_seconds
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STORE s0, alarm_status ;clear and disable alarm
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CALL alarm_drive ;turn off alarm control output port
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LOAD int_counter_lsb, 00 ;clear 'us' interrupt counter
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LOAD int_counter_msb, 00
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ENABLE INTERRUPT ;enable the 1us interrupts
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;
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;
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;Start of the main program loop.
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;
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;A prompt is transmitted to the UART transmitter and then
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;a command can be entered and interpreted.
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;
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;
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prompt_input: CALL send_prompt ;Prompt 'KCPSM3>'
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CALL receive_string ;obtain input string and maintain the time
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;
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;
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;Parse the string and perform actions as required
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;
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;
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;
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LOAD s1, string_start
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CALL fetch_char_from_memory
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COMPARE s0, character_CR ;carriage return does nothing
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JUMP Z, prompt_input
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COMPARE s0, character_T ;start of 'TIME' command?
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JUMP Z, test_for_TIME
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COMPARE s0, character_A ;start of 'ALARM' command?
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JUMP Z, test_for_ALARM
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;
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;trap other command starts here
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;
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bad_input_command: CALL send_Syntax_Error ;no valid command
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JUMP Z, prompt_input
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;
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;
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test_for_TIME: CALL fetch_char_from_memory
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COMPARE s0, character_I ;test for rest of 'TIME'
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_M
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_E
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JUMP NZ, bad_input_command
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;now have a valid TIME command to process
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CALL fetch_char_from_memory
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COMPARE s0, character_CR ;carriage return means display time
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JUMP NZ, set_time_command
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CALL transmit_time ;transmit time to UART
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JUMP prompt_input
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set_time_command: COMPARE s0, character_space
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JUMP NZ, bad_input_command
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CALL test_time_string ;interpret 'hh:mm:ss' string
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JUMP C, prompt_input ;test for invalid input
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STORE s6, real_time_hours ;set new time into clock
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STORE s5, real_time_minutes
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STORE s4, real_time_seconds
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STORE s0, ms_time_lsb ;clear 'ms' counter (s0=00)
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STORE s0, ms_time_msb
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CALL transmit_time ;transmit new time to UART
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JUMP prompt_input
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;
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;
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test_for_ALARM: CALL fetch_char_from_memory
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COMPARE s0, character_L ;test for rest of 'ALARM'
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_A
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_R
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_M
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JUMP NZ, bad_input_command
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;now have a valid ALARM command to process
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CALL fetch_char_from_memory
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COMPARE s0, character_CR ;carriage return means display alarm time
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JUMP NZ, set_alarm_command
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CALL transmit_alarm_time ;transmit time to UART
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JUMP prompt_input
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set_alarm_command: COMPARE s0, character_space ;test for ON or OFF command
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_O
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JUMP Z, set_alarm_on_off
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SUB s1, 01 ;move memory pointer back to first character of 'hh:mm:ss' string
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CALL test_time_string ;interpret 'hh:mm:ss' string
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JUMP C, prompt_input ;test for invalid input
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STORE s6, alarm_time_hours ;set new time into clock
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STORE s5, alarm_time_minutes
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STORE s4, alarm_time_seconds
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CALL transmit_alarm_time ;transmit new alarm time and status
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JUMP prompt_input
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set_alarm_on_off: CALL fetch_char_from_memory
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COMPARE s0, character_N ;test for 'ON'
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JUMP NZ, test_OFF
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CALL fetch_char_from_memory
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COMPARE s0, character_CR
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JUMP NZ, bad_input_command
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FETCH s0, alarm_status ;turn alarm on
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OR s0, alarm_armed
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STORE s0, alarm_status
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CALL transmit_alarm_time ;transmit alarm time and status
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JUMP prompt_input
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test_OFF: COMPARE s0, character_F ;test for for 'OFF'
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_F
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JUMP NZ, bad_input_command
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CALL fetch_char_from_memory
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COMPARE s0, character_CR
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JUMP NZ, bad_input_command
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LOAD s0, 00 ;turn alarm off and stop an active alarm
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STORE s0, alarm_status
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CALL alarm_drive ;turn off alarm
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CALL transmit_alarm_time ;transmit alarm time and status
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JUMP prompt_input
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;
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;
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;
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;
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;Read an 'hh:mm:ss' time string and provide new values.
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;
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;The string must be provided in successive scratch pad memory locations
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;with the s1 register containing the location of the first character.
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;
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;A correct time specification will result in the return of new values
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;as follows:-
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;
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; s6 = hours
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; s5 = minutes
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; s4 = seconds
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;
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;If the syntax is incorrect or values are not in the correct ranges an
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;'Invalid Time' message will be transmitted and the CARRY flag will be set
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;
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;Registers used s0, s1, s6, s5 and s4
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;
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test_time_string: CALL 2char_to_value ;obtain hours value
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JUMP C, invalid_time ;test for non-decimal characters
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LOAD s6, s2 ;remember hours
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ADD s1, 01 ;increment memory pointer past hours
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CALL fetch_char_from_memory
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COMPARE s0, character_colon ;test for colon
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JUMP NZ, invalid_time
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CALL 2char_to_value ;obtain minutes value
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JUMP C, invalid_time ;test for non-decimal characters
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LOAD s5, s2 ;remember minutes
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ADD s1, 01 ;increment memory pointer past minutes
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CALL fetch_char_from_memory
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COMPARE s0, character_colon ;test for colon
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JUMP NZ, invalid_time
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CALL 2char_to_value ;obtain seconds value
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JUMP C, invalid_time ;test for non-decimal characters
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LOAD s4, s2 ;remember minutes
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ADD s1, 01 ;increment memory pointer past seconds
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CALL fetch_char_from_memory
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COMPARE s0, character_CR ;finish with carriage return
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JUMP NZ, invalid_time
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;Have values for hh:mm:ss but need to test if each is valid range.
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COMPARE s6, hours_in_a_day
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JUMP NC, invalid_time
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COMPARE s5, minutes_in_an_hour
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JUMP NC, invalid_time
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COMPARE s4, seconds_in_a_minute
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JUMP NC, invalid_time
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LOAD s0, 00
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SR0 s0 ;reset CARRY flag (with s0=0)
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RETURN ;time string was OK
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invalid_time: CALL send_Invalid
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CALL send_space
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CALL send_Time
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LOAD s0, 01
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SR0 s0 ;set CARRY flag
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RETURN ;time string was bad
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| 265 |
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;
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| 266 |
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;
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| 267 |
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;Fetch character from memory, convert to upper case
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| 268 |
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;and increment memory pointer.
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| 269 |
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;
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| 270 |
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;The memory pointer is provided in register s1.
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;The character obtained is returned in register s0.
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;
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| 273 |
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;Registers used s0 and s1.
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;
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| 275 |
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fetch_char_from_memory: FETCH s0, (s1) ;read character
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| 276 |
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CALL upper_case ;convert to upper case
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ADD s1, 01 ;increment memory pointer
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| 278 |
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RETURN
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| 279 |
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;
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| 280 |
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;
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| 281 |
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;
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| 282 |
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;Read one character from the UART
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| 283 |
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;
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| 284 |
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;Character read will be returned in a register called 'UART_data' and will be
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| 285 |
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;echoed to the UART transmitter.
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| 286 |
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;
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| 287 |
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;The routine first tests the receiver FIFO buffer to see if data is present.
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| 288 |
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;If the FIFO is empty, the routine waits until there is a character to read.
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| 289 |
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;As this could take any amount of time the wait loop includes a call to the
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| 290 |
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;subroutine which updates the real time clock.
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| 291 |
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;
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| 292 |
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;Registers used s0 and UART_data
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| 293 |
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;
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| 294 |
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read_from_UART: INPUT s0, UART_status_port ;test Rx_FIFO buffer
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TEST s0, rx_data_present
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JUMP NZ, read_character
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| 297 |
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CALL update_time ;Perform useful operation whilst waiting
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| 298 |
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JUMP read_from_UART
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| 299 |
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read_character: INPUT UART_data, UART_read_port ;read from FIFO
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| 300 |
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CALL send_to_UART ;echo received character
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| 301 |
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RETURN
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| 302 |
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;
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| 303 |
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;
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| 304 |
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;
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| 305 |
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;Transmit one character to the UART
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| 306 |
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;
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| 307 |
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;Character supplied in register called 'UART_data'.
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;
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| 309 |
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;The routine first tests the transmit FIFO buffer to see if it is full.
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| 310 |
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;If the FIFO is full, the routine waits until there is space which could
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;be as long as it takes to transmit one complete character.
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| 312 |
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;
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; Baud Rate Time per Character (10 bits)
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; 9600 1,024us
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; 19200 521us
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; 38400 260us
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; 57600 174us
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| 318 |
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; 115200 87us
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| 319 |
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;
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| 320 |
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;Since this is a relatively long duration, the wait loop includes a
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| 321 |
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;call to the subroutine which updates the real time clock.
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| 322 |
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;
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| 323 |
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;Registers used s0
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;
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| 325 |
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send_to_UART: INPUT s0, UART_status_port ;test Tx_FIFO buffer
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TEST s0, tx_full
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JUMP Z, UART_write
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CALL update_time ;Perform useful operation whilst waiting
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| 329 |
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JUMP send_to_UART
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|
|
UART_write: OUTPUT UART_data, UART_write_port
|
| 331 |
|
|
RETURN
|
| 332 |
|
|
;
|
| 333 |
|
|
;
|
| 334 |
|
|
;
|
| 335 |
|
|
;
|
| 336 |
|
|
;Alarm output
|
| 337 |
|
|
;
|
| 338 |
|
|
;Uses the alarm status scratch pad memory to set or reset the alarm
|
| 339 |
|
|
;control bit on the alarm output port.
|
| 340 |
|
|
;
|
| 341 |
|
|
;Registers used s0
|
| 342 |
|
|
;
|
| 343 |
|
|
alarm_drive: FETCH s0, alarm_status ;read status
|
| 344 |
|
|
AND s0, alarm_active ;isolate bit0
|
| 345 |
|
|
OUTPUT s0, alarm_port
|
| 346 |
|
|
RETURN
|
| 347 |
|
|
;
|
| 348 |
|
|
;
|
| 349 |
|
|
;
|
| 350 |
|
|
;
|
| 351 |
|
|
;
|
| 352 |
|
|
;Transmit the time to the UART port in the format hh:mm:ss and end
|
| 353 |
|
|
;with a carriage return.
|
| 354 |
|
|
;
|
| 355 |
|
|
;The time to converted must be stored in 3 scratch pad memory locations as
|
| 356 |
|
|
;defined below. A register named 'store_pointer' must provide the address of
|
| 357 |
|
|
;first location.
|
| 358 |
|
|
;
|
| 359 |
|
|
; Address Data
|
| 360 |
|
|
;
|
| 361 |
|
|
; store_pointer ----> hours
|
| 362 |
|
|
; store_pointer + 1 ----> minutes
|
| 363 |
|
|
; store_pointer + 1 ----> seconds
|
| 364 |
|
|
;
|
| 365 |
|
|
;The routine first converts the time into an ASCII string stored in scratch
|
| 366 |
|
|
;pad memory starting at a location specified by a constant named 'string_start'.
|
| 367 |
|
|
;The string will then be transmitted.
|
| 368 |
|
|
;
|
| 369 |
|
|
;Registers used s0, s1, s2, 'store_pointer' and 'UART_data'.
|
| 370 |
|
|
;
|
| 371 |
|
|
transmit_time: LOAD store_pointer, real_time_hours ;locate current time in memory
|
| 372 |
|
|
CALL time_to_ASCII
|
| 373 |
|
|
CALL transmit_string
|
| 374 |
|
|
RETURN
|
| 375 |
|
|
;
|
| 376 |
|
|
;
|
| 377 |
|
|
;Transmit the alarm time and status to the UART port in the format hh:mm:ss and
|
| 378 |
|
|
;ending with carriage return.
|
| 379 |
|
|
;
|
| 380 |
|
|
;The alarm time to converted must be stored in 3 scratch pad memory locations as
|
| 381 |
|
|
;defined below. A register named 'store_pointer' must provide the address of
|
| 382 |
|
|
;first location.
|
| 383 |
|
|
;
|
| 384 |
|
|
; Address Data
|
| 385 |
|
|
;
|
| 386 |
|
|
; store_pointer ----> hours
|
| 387 |
|
|
; store_pointer + 1 ----> minutes
|
| 388 |
|
|
; store_pointer + 1 ----> seconds
|
| 389 |
|
|
;
|
| 390 |
|
|
;The routine first converts the time into an ASCII string stored in scratch
|
| 391 |
|
|
;pad memory starting at a location specified by a constant named 'string_start'.
|
| 392 |
|
|
;The string will then be transmitted.
|
| 393 |
|
|
;
|
| 394 |
|
|
;Registers used s0, s1, s2, 'store_pointer' and 'UART_data'.
|
| 395 |
|
|
;
|
| 396 |
|
|
transmit_alarm_time: LOAD store_pointer, alarm_time_hours ;locate alarm time in memory
|
| 397 |
|
|
CALL time_to_ASCII
|
| 398 |
|
|
CALL transmit_string
|
| 399 |
|
|
CALL send_Alarm
|
| 400 |
|
|
CALL send_space
|
| 401 |
|
|
FETCH s0, alarm_status ;read alarm status
|
| 402 |
|
|
TEST s0, alarm_active ;test for active
|
| 403 |
|
|
JUMP Z, test_armed
|
| 404 |
|
|
CALL send_Active
|
| 405 |
|
|
RETURN
|
| 406 |
|
|
test_armed: TEST s0, alarm_armed ;test for on
|
| 407 |
|
|
JUMP Z, alarm_is_off
|
| 408 |
|
|
CALL send_ON
|
| 409 |
|
|
RETURN
|
| 410 |
|
|
alarm_is_off: CALL send_OFF
|
| 411 |
|
|
RETURN
|
| 412 |
|
|
;
|
| 413 |
|
|
;
|
| 414 |
|
|
;Transmit ASCII string to UART
|
| 415 |
|
|
;
|
| 416 |
|
|
;An ASCII string must be provided in scratch pad memory commencing at the
|
| 417 |
|
|
;location specified by a constant named 'string_start'. The string must
|
| 418 |
|
|
;end with a carriage return (0D).
|
| 419 |
|
|
;
|
| 420 |
|
|
;Registers used s1 and 'UART_data'.
|
| 421 |
|
|
; s0 is then used in subroutine 'send_to_UART'
|
| 422 |
|
|
;
|
| 423 |
|
|
transmit_string: LOAD s1, string_start ;locate start of string
|
| 424 |
|
|
next_char_tx: FETCH UART_data, (s1) ;read character from memory
|
| 425 |
|
|
CALL send_to_UART ;transmit character
|
| 426 |
|
|
COMPARE UART_data, character_CR ;test for last character
|
| 427 |
|
|
RETURN Z
|
| 428 |
|
|
ADD s1, 01 ;move to next character
|
| 429 |
|
|
JUMP next_char_tx
|
| 430 |
|
|
;
|
| 431 |
|
|
;
|
| 432 |
|
|
;Receive ASCII string from UART
|
| 433 |
|
|
;
|
| 434 |
|
|
;An ASCII string will be read from the UART and stored in scratch pad memory
|
| 435 |
|
|
;commencing at the location specified by a constant named 'string_start'.
|
| 436 |
|
|
;The string will will have a maximum length of 16 characters including a
|
| 437 |
|
|
;carriage return (0D) denoting the end of the string.
|
| 438 |
|
|
;
|
| 439 |
|
|
;As each character is read, it is echoed to the UART transmitter.
|
| 440 |
|
|
;Some minor editing is supported using backspace (BS=08) which is used
|
| 441 |
|
|
;to adjust what is stored in scratch pad memory and adjust the display
|
| 442 |
|
|
;on the terminal screen using characters sent to the UART transmitter.
|
| 443 |
|
|
;
|
| 444 |
|
|
;A test is made for the receiver FIFO becoming full. A full status is treated as
|
| 445 |
|
|
;a potential error situation and will result in a 'Overflow Error' message being
|
| 446 |
|
|
;transmitted to the UART, the receiver FIFO being purged of all data and an
|
| 447 |
|
|
;empty string being stored (carriage return at first location).
|
| 448 |
|
|
;
|
| 449 |
|
|
;Registers used s0, s1, s2 and 'UART_data'.
|
| 450 |
|
|
;
|
| 451 |
|
|
receive_string: LOAD s1, string_start ;locate start of string
|
| 452 |
|
|
LOAD s2, s1 ;compute 16 character address
|
| 453 |
|
|
ADD s2, 10
|
| 454 |
|
|
receive_full_test: INPUT s0, UART_status_port ;test Rx_FIFO buffer for full
|
| 455 |
|
|
TEST s0, rx_full
|
| 456 |
|
|
JUMP NZ, read_error
|
| 457 |
|
|
CALL read_from_UART ;obtain and echo character
|
| 458 |
|
|
STORE UART_data, (s1) ;write to memory
|
| 459 |
|
|
COMPARE UART_data, character_CR ;test for end of string
|
| 460 |
|
|
RETURN Z
|
| 461 |
|
|
COMPARE UART_data, character_BS ;test for back space
|
| 462 |
|
|
JUMP Z, BS_edit
|
| 463 |
|
|
ADD s1, 01 ;increment memory pointer
|
| 464 |
|
|
COMPARE s1, s2 ;test for pointer exceeding 16 characters
|
| 465 |
|
|
JUMP NZ, receive_full_test ;next character
|
| 466 |
|
|
CALL send_backspace ;hold end of string position on terminal display
|
| 467 |
|
|
BS_edit: SUB s1, 01 ;memory pointer back one
|
| 468 |
|
|
COMPARE s1, string_start ;test for under flow
|
| 469 |
|
|
JUMP C, string_start_again
|
| 470 |
|
|
CALL send_space ;clear character at current position
|
| 471 |
|
|
CALL send_backspace ;position cursor
|
| 472 |
|
|
JUMP receive_full_test ;next character
|
| 473 |
|
|
string_start_again: CALL send_greater_than ;restore '>' at prompt
|
| 474 |
|
|
JUMP receive_string ;begin again
|
| 475 |
|
|
;Receiver buffer overflow condition
|
| 476 |
|
|
read_error: CALL send_CR ;Transmit error message
|
| 477 |
|
|
STORE UART_data, string_start ;empty string in memory (start with CR)
|
| 478 |
|
|
CALL send_Overflow_Error
|
| 479 |
|
|
CALL send_CR
|
| 480 |
|
|
clear_UART_Rx_loop: INPUT s0, UART_status_port ;test Rx_FIFO buffer for data
|
| 481 |
|
|
TEST s0, rx_data_present
|
| 482 |
|
|
RETURN Z ;finish when buffer is empty
|
| 483 |
|
|
INPUT UART_data, UART_read_port ;read from FIFO and ignore
|
| 484 |
|
|
JUMP clear_UART_Rx_loop
|
| 485 |
|
|
;
|
| 486 |
|
|
;
|
| 487 |
|
|
;
|
| 488 |
|
|
;Send Carriage Return to the UART
|
| 489 |
|
|
;
|
| 490 |
|
|
send_CR: LOAD UART_data, character_CR
|
| 491 |
|
|
CALL send_to_UART
|
| 492 |
|
|
RETURN
|
| 493 |
|
|
;
|
| 494 |
|
|
;
|
| 495 |
|
|
;
|
| 496 |
|
|
;Send a space to the UART
|
| 497 |
|
|
;
|
| 498 |
|
|
send_space: LOAD UART_data, character_space
|
| 499 |
|
|
CALL send_to_UART
|
| 500 |
|
|
RETURN
|
| 501 |
|
|
;
|
| 502 |
|
|
;
|
| 503 |
|
|
;Send a back space to the UART
|
| 504 |
|
|
;
|
| 505 |
|
|
send_backspace: LOAD UART_data, character_BS
|
| 506 |
|
|
CALL send_to_UART
|
| 507 |
|
|
RETURN
|
| 508 |
|
|
;
|
| 509 |
|
|
;Send 'Syntax Error' to the UART
|
| 510 |
|
|
;
|
| 511 |
|
|
send_Syntax_Error: LOAD UART_data, character_S
|
| 512 |
|
|
CALL send_to_UART
|
| 513 |
|
|
LOAD UART_data, character_y
|
| 514 |
|
|
CALL send_to_UART
|
| 515 |
|
|
LOAD UART_data, character_n
|
| 516 |
|
|
CALL send_to_UART
|
| 517 |
|
|
LOAD UART_data, character_t
|
| 518 |
|
|
CALL send_to_UART
|
| 519 |
|
|
LOAD UART_data, character_a
|
| 520 |
|
|
CALL send_to_UART
|
| 521 |
|
|
LOAD UART_data, character_x
|
| 522 |
|
|
CALL send_to_UART
|
| 523 |
|
|
JUMP send_space_Error
|
| 524 |
|
|
;
|
| 525 |
|
|
;Send 'Overflow Error' to the UART
|
| 526 |
|
|
;
|
| 527 |
|
|
send_Overflow_Error: LOAD UART_data, character_O
|
| 528 |
|
|
CALL send_to_UART
|
| 529 |
|
|
LOAD UART_data, character_v
|
| 530 |
|
|
CALL send_to_UART
|
| 531 |
|
|
LOAD UART_data, character_e
|
| 532 |
|
|
CALL send_to_UART
|
| 533 |
|
|
LOAD UART_data, character_r
|
| 534 |
|
|
CALL send_to_UART
|
| 535 |
|
|
LOAD UART_data, character_f
|
| 536 |
|
|
CALL send_to_UART
|
| 537 |
|
|
LOAD UART_data, character_l
|
| 538 |
|
|
CALL send_to_UART
|
| 539 |
|
|
LOAD UART_data, character_o
|
| 540 |
|
|
CALL send_to_UART
|
| 541 |
|
|
LOAD UART_data, character_w
|
| 542 |
|
|
CALL send_to_UART
|
| 543 |
|
|
send_space_Error: CALL send_space
|
| 544 |
|
|
;
|
| 545 |
|
|
;Send 'Error' to the UART
|
| 546 |
|
|
;
|
| 547 |
|
|
send_Error: LOAD UART_data, character_E
|
| 548 |
|
|
CALL send_to_UART
|
| 549 |
|
|
LOAD UART_data, character_r
|
| 550 |
|
|
CALL send_to_UART
|
| 551 |
|
|
CALL send_to_UART
|
| 552 |
|
|
LOAD UART_data, character_o
|
| 553 |
|
|
CALL send_to_UART
|
| 554 |
|
|
LOAD UART_data, character_r
|
| 555 |
|
|
CALL send_to_UART
|
| 556 |
|
|
RETURN
|
| 557 |
|
|
;
|
| 558 |
|
|
;Send 'KCPSM3>' prompt to the UART
|
| 559 |
|
|
;
|
| 560 |
|
|
send_prompt: CALL send_CR ;start new line
|
| 561 |
|
|
LOAD UART_data, character_K
|
| 562 |
|
|
CALL send_to_UART
|
| 563 |
|
|
LOAD UART_data, character_C
|
| 564 |
|
|
CALL send_to_UART
|
| 565 |
|
|
LOAD UART_data, character_P
|
| 566 |
|
|
CALL send_to_UART
|
| 567 |
|
|
LOAD UART_data, character_S
|
| 568 |
|
|
CALL send_to_UART
|
| 569 |
|
|
LOAD UART_data, character_M
|
| 570 |
|
|
CALL send_to_UART
|
| 571 |
|
|
LOAD UART_data, character_3
|
| 572 |
|
|
CALL send_to_UART
|
| 573 |
|
|
;
|
| 574 |
|
|
;Send '>' character to the UART
|
| 575 |
|
|
;
|
| 576 |
|
|
send_greater_than: LOAD UART_data, character_greater_than
|
| 577 |
|
|
CALL send_to_UART
|
| 578 |
|
|
RETURN
|
| 579 |
|
|
;
|
| 580 |
|
|
;Send 'Invalid' string to the UART
|
| 581 |
|
|
;
|
| 582 |
|
|
send_Invalid: LOAD UART_data, character_I
|
| 583 |
|
|
CALL send_to_UART
|
| 584 |
|
|
LOAD UART_data, character_n
|
| 585 |
|
|
CALL send_to_UART
|
| 586 |
|
|
LOAD UART_data, character_v
|
| 587 |
|
|
CALL send_to_UART
|
| 588 |
|
|
LOAD UART_data, character_a
|
| 589 |
|
|
CALL send_to_UART
|
| 590 |
|
|
LOAD UART_data, character_l
|
| 591 |
|
|
CALL send_to_UART
|
| 592 |
|
|
LOAD UART_data, character_i
|
| 593 |
|
|
CALL send_to_UART
|
| 594 |
|
|
LOAD UART_data, character_d
|
| 595 |
|
|
CALL send_to_UART
|
| 596 |
|
|
RETURN
|
| 597 |
|
|
;
|
| 598 |
|
|
;Send 'Time' string to the UART
|
| 599 |
|
|
;
|
| 600 |
|
|
send_Time: LOAD UART_data, character_T
|
| 601 |
|
|
CALL send_to_UART
|
| 602 |
|
|
LOAD UART_data, character_i
|
| 603 |
|
|
CALL send_to_UART
|
| 604 |
|
|
LOAD UART_data, character_m
|
| 605 |
|
|
CALL send_to_UART
|
| 606 |
|
|
LOAD UART_data, character_e
|
| 607 |
|
|
CALL send_to_UART
|
| 608 |
|
|
RETURN
|
| 609 |
|
|
;
|
| 610 |
|
|
;Send 'Alarm' string to the UART
|
| 611 |
|
|
;
|
| 612 |
|
|
send_Alarm: LOAD UART_data, character_A
|
| 613 |
|
|
CALL send_to_UART
|
| 614 |
|
|
LOAD UART_data, character_l
|
| 615 |
|
|
CALL send_to_UART
|
| 616 |
|
|
LOAD UART_data, character_a
|
| 617 |
|
|
CALL send_to_UART
|
| 618 |
|
|
LOAD UART_data, character_r
|
| 619 |
|
|
CALL send_to_UART
|
| 620 |
|
|
LOAD UART_data, character_m
|
| 621 |
|
|
CALL send_to_UART
|
| 622 |
|
|
RETURN
|
| 623 |
|
|
;
|
| 624 |
|
|
;Send 'OFF' string to the UART
|
| 625 |
|
|
;
|
| 626 |
|
|
send_OFF: LOAD UART_data, character_O
|
| 627 |
|
|
CALL send_to_UART
|
| 628 |
|
|
LOAD UART_data, character_F
|
| 629 |
|
|
CALL send_to_UART
|
| 630 |
|
|
CALL send_to_UART
|
| 631 |
|
|
RETURN
|
| 632 |
|
|
;
|
| 633 |
|
|
;Send 'ON' string to the UART
|
| 634 |
|
|
;
|
| 635 |
|
|
send_ON: LOAD UART_data, character_O
|
| 636 |
|
|
CALL send_to_UART
|
| 637 |
|
|
LOAD UART_data, character_N
|
| 638 |
|
|
CALL send_to_UART
|
| 639 |
|
|
RETURN
|
| 640 |
|
|
;
|
| 641 |
|
|
;Send 'Active' string to the UART
|
| 642 |
|
|
;
|
| 643 |
|
|
send_Active: LOAD UART_data, character_A
|
| 644 |
|
|
CALL send_to_UART
|
| 645 |
|
|
LOAD UART_data, character_c
|
| 646 |
|
|
CALL send_to_UART
|
| 647 |
|
|
LOAD UART_data, character_t
|
| 648 |
|
|
CALL send_to_UART
|
| 649 |
|
|
LOAD UART_data, character_i
|
| 650 |
|
|
CALL send_to_UART
|
| 651 |
|
|
LOAD UART_data, character_v
|
| 652 |
|
|
CALL send_to_UART
|
| 653 |
|
|
LOAD UART_data, character_e
|
| 654 |
|
|
CALL send_to_UART
|
| 655 |
|
|
RETURN
|
| 656 |
|
|
;
|
| 657 |
|
|
;
|
| 658 |
|
|
;Convert time to ASCII string in scratch pad memory.
|
| 659 |
|
|
;
|
| 660 |
|
|
;The time to converted must be stored in 3 scratch pad memory locations as
|
| 661 |
|
|
;defined below. A register named 'store_pointer' must provide the address of
|
| 662 |
|
|
;first location.
|
| 663 |
|
|
;
|
| 664 |
|
|
; Address Data
|
| 665 |
|
|
;
|
| 666 |
|
|
; store_pointer ----> hours
|
| 667 |
|
|
; store_pointer + 1 ----> minutes
|
| 668 |
|
|
; store_pointer + 1 ----> seconds
|
| 669 |
|
|
;
|
| 670 |
|
|
;The resulting ASCII string will be stored in scratch pad memory starting at
|
| 671 |
|
|
;a location specified by a constant named 'string_start'. The string will
|
| 672 |
|
|
;take the format hh:mm:ss and end with a carriage return.
|
| 673 |
|
|
;
|
| 674 |
|
|
;Registers used s0, s1, s2 and 'store_pointer'.
|
| 675 |
|
|
;
|
| 676 |
|
|
time_to_ASCII: LOAD s2, string_start ;location for string
|
| 677 |
|
|
FETCH s0, (store_pointer) ;read hours value
|
| 678 |
|
|
CALL decimal_to_ASCII ;convert to ASCII
|
| 679 |
|
|
STORE s1, (s2) ;write hours to string
|
| 680 |
|
|
ADD s2, 01
|
| 681 |
|
|
STORE s0, (s2)
|
| 682 |
|
|
ADD s2, 01
|
| 683 |
|
|
LOAD s0, character_colon ;write ':' to string
|
| 684 |
|
|
STORE s0, (s2)
|
| 685 |
|
|
ADD s2, 01
|
| 686 |
|
|
ADD store_pointer, 01 ;move to minutes
|
| 687 |
|
|
FETCH s0, (store_pointer) ;read minutes value
|
| 688 |
|
|
CALL decimal_to_ASCII ;convert to ASCII
|
| 689 |
|
|
STORE s1, (s2) ;write minutes to string
|
| 690 |
|
|
ADD s2, 01
|
| 691 |
|
|
STORE s0, (s2)
|
| 692 |
|
|
ADD s2, 01
|
| 693 |
|
|
LOAD s0, character_colon ;write ':' to string
|
| 694 |
|
|
STORE s0, (s2)
|
| 695 |
|
|
ADD s2, 01
|
| 696 |
|
|
ADD store_pointer, 01 ;move to seconds
|
| 697 |
|
|
FETCH s0, (store_pointer) ;read seconds value
|
| 698 |
|
|
CALL decimal_to_ASCII ;convert to ASCII
|
| 699 |
|
|
STORE s1, (s2) ;write seconds to string
|
| 700 |
|
|
ADD s2, 01
|
| 701 |
|
|
STORE s0, (s2)
|
| 702 |
|
|
ADD s2, 01
|
| 703 |
|
|
LOAD s0, character_CR ;finish string with carriage return
|
| 704 |
|
|
STORE s0, (s2)
|
| 705 |
|
|
RETURN
|
| 706 |
|
|
;
|
| 707 |
|
|
;Convert value provided in register s0 into ASCII characters
|
| 708 |
|
|
;
|
| 709 |
|
|
;The value provided must in the range 0 to 99 and will be converted into
|
| 710 |
|
|
;two ASCII characters.
|
| 711 |
|
|
; The number of 'tens' will be representd by an ASCII character returned in register s1.
|
| 712 |
|
|
; The number of 'units' will be representd by an ASCII character returned in register s0.
|
| 713 |
|
|
;
|
| 714 |
|
|
;The ASCII representations of '0' to '9' are 30 to 39 hexadecimal which is simply 30 hex added to
|
| 715 |
|
|
;the actual decimal value.
|
| 716 |
|
|
;
|
| 717 |
|
|
;Registers used s0 and s1.
|
| 718 |
|
|
;
|
| 719 |
|
|
decimal_to_ASCII: LOAD s1, 30 ;load 'tens' counter with ASCII for '0'
|
| 720 |
|
|
test_for_ten: ADD s1, 01 ;increment 'tens' value
|
| 721 |
|
|
SUB s0, 0A ;try to subtract 10 from the supplied value
|
| 722 |
|
|
JUMP NC, test_for_ten ;repeat if subtraction was possible without underflow.
|
| 723 |
|
|
SUB s1, 01 ;'tens' value one less ten due to underflow
|
| 724 |
|
|
ADD s0, 3A ;restore units value (the remainder) and convert to ASCII
|
| 725 |
|
|
RETURN
|
| 726 |
|
|
;
|
| 727 |
|
|
;
|
| 728 |
|
|
;
|
| 729 |
|
|
;
|
| 730 |
|
|
;Real Time Clock
|
| 731 |
|
|
;
|
| 732 |
|
|
;Uses the 1us interrupt counter [int_counter_msb,int_counter_lsb] to determine how many
|
| 733 |
|
|
;micro-seconds have elapsed since the last update. This allows for just over 65ms between
|
| 734 |
|
|
;updates. Complete multiples of 1000us are used to update a 16-bit milli-second counter held
|
| 735 |
|
|
;in scratch pad memory locations [ms_time_stamp_msb,ms_time_stamp_msb] which in turn
|
| 736 |
|
|
;is used to update the real time hours, minutes and seconds clock held in scratch pad
|
| 737 |
|
|
;memory locations 'real_time_hours', 'real_time_minutes' and 'real_time_seconds'.
|
| 738 |
|
|
;
|
| 739 |
|
|
;The routine uses default register names s0,s1,s2,s3,s4,s5. These are preserved in scratch pad
|
| 740 |
|
|
;memory during the routine and restored before returning.
|
| 741 |
|
|
;
|
| 742 |
|
|
;Useful constants for real time clock operations
|
| 743 |
|
|
;
|
| 744 |
|
|
CONSTANT count_1000_lsb, E8 ;lower 8-bits of 1000 count value
|
| 745 |
|
|
CONSTANT count_1000_msb, 03 ;upper 8-bits of 1000 count value
|
| 746 |
|
|
CONSTANT hours_in_a_day, 18 ;24 hours in a day
|
| 747 |
|
|
CONSTANT minutes_in_an_hour, 3C ;60 minutes in an hour
|
| 748 |
|
|
CONSTANT seconds_in_a_minute, 3C ;60 seconds in a minute
|
| 749 |
|
|
;
|
| 750 |
|
|
update_time: STORE s0, time_preserve0 ;preserve contents of registers used during routine
|
| 751 |
|
|
STORE s1, time_preserve1
|
| 752 |
|
|
STORE s2, time_preserve2
|
| 753 |
|
|
STORE s3, time_preserve3
|
| 754 |
|
|
STORE s4, time_preserve4
|
| 755 |
|
|
STORE s5, time_preserve5
|
| 756 |
|
|
;
|
| 757 |
|
|
FETCH s2, us_time_stamp_lsb ;read the previous 'us' time stamp into [s3,s2]
|
| 758 |
|
|
FETCH s3, us_time_stamp_msb
|
| 759 |
|
|
DISABLE INTERRUPT ;Read and store current 'us' time stamp provided by the interrupt
|
| 760 |
|
|
STORE int_counter_lsb, us_time_stamp_lsb ;counter. Interrupts are disabled to ensure that both bytes relate
|
| 761 |
|
|
STORE int_counter_msb, us_time_stamp_msb ;to the same count value.
|
| 762 |
|
|
ENABLE INTERRUPT
|
| 763 |
|
|
FETCH s4, us_time_stamp_lsb ;read the new 'us' time stamp in [s5,s4]
|
| 764 |
|
|
FETCH s5, us_time_stamp_msb ;
|
| 765 |
|
|
SUB s4, s2 ;calculate 'us' time difference [s5,s4] = [s5,s4] - [s3,s2]
|
| 766 |
|
|
SUBCY s5, s3 ; (This works correctly even if counter has rolled over)
|
| 767 |
|
|
FETCH s2, us_time_lsb ;read current 'us' time into [s3,s2]
|
| 768 |
|
|
FETCH s3, us_time_msb
|
| 769 |
|
|
ADD s2, s4 ;add on the elapsed 'us' value [s3,s2] = [s3,s2] + [s5,s4]
|
| 770 |
|
|
ADDCY s3, s5
|
| 771 |
|
|
;determine how many 1000us (1ms) units there are (if any) in current 'us' time
|
| 772 |
|
|
LOAD s0, 00 ;reset 'ms' counter
|
| 773 |
|
|
test_1000us: SUB s2, count_1000_lsb ;subtract 1000 from [s3,s2]
|
| 774 |
|
|
SUBCY s3, count_1000_msb
|
| 775 |
|
|
JUMP C, store_us_time ;Carry indicates [s3,s2] was less than 1000us
|
| 776 |
|
|
ADD s0, 01 ;increment 'ms' elapsed because [s3,s2] was more or equal to 1000us
|
| 777 |
|
|
JUMP test_1000us ;repeat to see if more than 1ms has elapsed
|
| 778 |
|
|
store_us_time: ADD s2, count_1000_lsb ;add 1000 to restore 'us' value
|
| 779 |
|
|
ADDCY s3, count_1000_msb
|
| 780 |
|
|
STORE s2, us_time_lsb ;store the current value of 'us'
|
| 781 |
|
|
STORE s3, us_time_msb
|
| 782 |
|
|
;s0 holds the number of 'ms' elapsed since last update (if any).
|
| 783 |
|
|
FETCH s2, ms_time_lsb ;read current 'ms' time into [s3,s2]
|
| 784 |
|
|
FETCH s3, ms_time_msb
|
| 785 |
|
|
ADD s2, s0 ;add on the elapsed 'ms' value [s3,s2] = [s3,s2] + s0
|
| 786 |
|
|
ADDCY s3, 00
|
| 787 |
|
|
;determine if there are now more than 1000ms to form 1 second.
|
| 788 |
|
|
LOAD s0, 00 ;reset 'second' counter
|
| 789 |
|
|
SUB s2, count_1000_lsb ;subtract 1000 from [s3,s2]
|
| 790 |
|
|
SUBCY s3, count_1000_msb
|
| 791 |
|
|
JUMP C, restore_ms_time ;Carry indicates [s3,s2] was less than 1000ms
|
| 792 |
|
|
ADD s0, 01 ;increment 'second' elapsed because [s3,s2] was more or equal to 1000ms
|
| 793 |
|
|
JUMP store_ms_time ;new value of 'ms' is remainder of subtraction
|
| 794 |
|
|
restore_ms_time: ADD s2, count_1000_lsb ;add 1000 to restore 'ms' value
|
| 795 |
|
|
ADDCY s3, count_1000_msb
|
| 796 |
|
|
store_ms_time: STORE s2, ms_time_lsb ;store the current value of 'ms'
|
| 797 |
|
|
STORE s3, ms_time_msb
|
| 798 |
|
|
;s0 currently determines if one second needs to be added to the hh:mm:ss clock time
|
| 799 |
|
|
FETCH s1, real_time_seconds ;read seconds
|
| 800 |
|
|
ADD s1, s0 ;add one second if required by s0
|
| 801 |
|
|
COMPARE s1, seconds_in_a_minute ;test for 1 minute
|
| 802 |
|
|
JUMP Z, inc_minutes
|
| 803 |
|
|
STORE s1, real_time_seconds ;store updated seconds
|
| 804 |
|
|
JUMP time_update_complete
|
| 805 |
|
|
inc_minutes: LOAD s1, 00 ;seconds become zero
|
| 806 |
|
|
STORE s1, real_time_seconds
|
| 807 |
|
|
FETCH s1, real_time_minutes ;read minutes
|
| 808 |
|
|
ADD s1, 01 ;increment minutes
|
| 809 |
|
|
COMPARE s1, minutes_in_an_hour ;test for 1 hour
|
| 810 |
|
|
JUMP Z, inc_hours
|
| 811 |
|
|
STORE s1, real_time_minutes ;store updated minutes
|
| 812 |
|
|
JUMP time_update_complete
|
| 813 |
|
|
inc_hours: LOAD s1, 00 ;minutes become zero
|
| 814 |
|
|
STORE s1, real_time_minutes
|
| 815 |
|
|
FETCH s1, real_time_hours ;read hours
|
| 816 |
|
|
ADD s1, 01 ;increment hours
|
| 817 |
|
|
COMPARE s1, hours_in_a_day ;test for 24 hours
|
| 818 |
|
|
JUMP Z, reset_hours
|
| 819 |
|
|
STORE s1, real_time_hours ;store updated hours
|
| 820 |
|
|
JUMP time_update_complete
|
| 821 |
|
|
reset_hours: LOAD s1, 00 ;hours become zero
|
| 822 |
|
|
STORE s1, real_time_hours
|
| 823 |
|
|
;
|
| 824 |
|
|
;With the time updated, there is then a test for time=alarm time
|
| 825 |
|
|
;
|
| 826 |
|
|
time_update_complete: FETCH s0, real_time_hours
|
| 827 |
|
|
FETCH s1, alarm_time_hours ;compare hours
|
| 828 |
|
|
COMPARE s0, s1
|
| 829 |
|
|
JUMP NZ, finish_update
|
| 830 |
|
|
FETCH s0, real_time_minutes ;compare minutes
|
| 831 |
|
|
FETCH s1, alarm_time_minutes
|
| 832 |
|
|
COMPARE s0, s1
|
| 833 |
|
|
JUMP NZ, finish_update
|
| 834 |
|
|
FETCH s0, real_time_seconds ;compare seconds
|
| 835 |
|
|
FETCH s1, alarm_time_seconds
|
| 836 |
|
|
COMPARE s0, s1
|
| 837 |
|
|
JUMP NZ, finish_update
|
| 838 |
|
|
FETCH s0, alarm_status ;test if alarm is turned on
|
| 839 |
|
|
TEST s0, alarm_armed
|
| 840 |
|
|
JUMP Z, finish_update ;alarm was off
|
| 841 |
|
|
OR s0, alarm_active ;activate alarm
|
| 842 |
|
|
STORE s0, alarm_status
|
| 843 |
|
|
CALL alarm_drive
|
| 844 |
|
|
finish_update: FETCH s0, time_preserve0 ;restore the register contents
|
| 845 |
|
|
FETCH s1, time_preserve1
|
| 846 |
|
|
FETCH s2, time_preserve2
|
| 847 |
|
|
FETCH s3, time_preserve3
|
| 848 |
|
|
FETCH s4, time_preserve4
|
| 849 |
|
|
FETCH s5, time_preserve5
|
| 850 |
|
|
RETURN
|
| 851 |
|
|
;
|
| 852 |
|
|
;Convert character to upper case
|
| 853 |
|
|
;
|
| 854 |
|
|
;The character supplied in register s0.
|
| 855 |
|
|
;If the character is in the range 'a' to 'z', it is converted
|
| 856 |
|
|
;to the equivalent upper case character in the range 'A' to 'Z'.
|
| 857 |
|
|
;All other characters remain unchanged.
|
| 858 |
|
|
;
|
| 859 |
|
|
;Registers used s0.
|
| 860 |
|
|
;
|
| 861 |
|
|
upper_case: COMPARE s0, 61 ;eliminate character codes below 'a' (61 hex)
|
| 862 |
|
|
RETURN C
|
| 863 |
|
|
COMPARE s0, 7B ;eliminate character codes above 'z' (7A hex)
|
| 864 |
|
|
RETURN NC
|
| 865 |
|
|
AND s0, DF ;mask bit5 to convert to upper case
|
| 866 |
|
|
RETURN
|
| 867 |
|
|
;
|
| 868 |
|
|
;
|
| 869 |
|
|
;Convert character '0' to '9' to numerical value in range 0 to 9
|
| 870 |
|
|
;
|
| 871 |
|
|
;The character supplied in register s0. If the character is in the
|
| 872 |
|
|
;range '0' to '9', it is converted to the equivalent decimal value.
|
| 873 |
|
|
;Characters not in the range '0' to '9' are signified by the return
|
| 874 |
|
|
;with the CARRY flag set.
|
| 875 |
|
|
;
|
| 876 |
|
|
;Registers used s0.
|
| 877 |
|
|
;
|
| 878 |
|
|
1char_to_value: ADD s0, C6 ;reject character codes above '9' (39 hex)
|
| 879 |
|
|
RETURN C ;carry flag is set
|
| 880 |
|
|
SUB s0, F6 ;reject character codes below '0' (30 hex)
|
| 881 |
|
|
RETURN ;carry is set if value not in range
|
| 882 |
|
|
;
|
| 883 |
|
|
;
|
| 884 |
|
|
;Determine the numerical value of a two character decimal string held in
|
| 885 |
|
|
;scratch pad memory such the result is in the range 0 to 99 (00 to 63 hex).
|
| 886 |
|
|
;
|
| 887 |
|
|
;The string must be stored as in two consecutive memory locations and the
|
| 888 |
|
|
;location of the first (tens) character supplied in the s1 register.
|
| 889 |
|
|
;The result is provided in register s2. Strings not using characters in the
|
| 890 |
|
|
;range '0' to '9' are signified by the return with the CARRY flag set.
|
| 891 |
|
|
;
|
| 892 |
|
|
;Registers used s0, s1 and s2.
|
| 893 |
|
|
;
|
| 894 |
|
|
2char_to_value: FETCH s0, (s1) ;read 'tens' character
|
| 895 |
|
|
CALL 1char_to_value ;convert to numerical value
|
| 896 |
|
|
RETURN C ;bad character - CARRY set
|
| 897 |
|
|
LOAD s2, s0
|
| 898 |
|
|
SL0 s2 ;multiply 'tens' value by 10 (0A hex)
|
| 899 |
|
|
SL0 s2
|
| 900 |
|
|
ADD s2, s0
|
| 901 |
|
|
SL0 s2
|
| 902 |
|
|
ADD s1, 01 ;read 'units' character
|
| 903 |
|
|
FETCH s0, (s1)
|
| 904 |
|
|
CALL 1char_to_value ;convert to numerical value
|
| 905 |
|
|
RETURN C ;bad character - CARRY set
|
| 906 |
|
|
ADD s2, s0 ;add units to result and clear CARRY flag
|
| 907 |
|
|
RETURN
|
| 908 |
|
|
;
|
| 909 |
|
|
;
|
| 910 |
|
|
;Interrupt service routine (ISR)
|
| 911 |
|
|
;
|
| 912 |
|
|
;The interrupt is used to increment a 16-bit counter formed with two registers
|
| 913 |
|
|
;called [int_counter_msb,int_counter_lsb]. This provides a count of the number
|
| 914 |
|
|
;of micro-seconds elapsed. The counter is 'free running' in that it will count
|
| 915 |
|
|
;up to 65,535 and then roll over to zero. The count value is then used in other
|
| 916 |
|
|
;parts of the program as required and where it is less time critical.
|
| 917 |
|
|
;
|
| 918 |
|
|
;The ISR only uses the specified counter registers
|
| 919 |
|
|
;
|
| 920 |
|
|
ADDRESS 3FC
|
| 921 |
|
|
ISR: ADD int_counter_lsb, 01 ;add 1us to 16-bit counter
|
| 922 |
|
|
ADDCY int_counter_msb, 00
|
| 923 |
|
|
RETURNI ENABLE
|
| 924 |
|
|
;
|
| 925 |
|
|
;Interrupt vector
|
| 926 |
|
|
;
|
| 927 |
|
|
ADDRESS 3FF
|
| 928 |
|
|
JUMP ISR
|
| 929 |
|
|
;
|
| 930 |
|
|
;
|
| 931 |
|
|
;Useful constants
|
| 932 |
|
|
;
|
| 933 |
|
|
;
|
| 934 |
|
|
;ASCII table
|
| 935 |
|
|
;
|
| 936 |
|
|
CONSTANT character_a, 61
|
| 937 |
|
|
CONSTANT character_b, 62
|
| 938 |
|
|
CONSTANT character_c, 63
|
| 939 |
|
|
CONSTANT character_d, 64
|
| 940 |
|
|
CONSTANT character_e, 65
|
| 941 |
|
|
CONSTANT character_f, 66
|
| 942 |
|
|
CONSTANT character_g, 67
|
| 943 |
|
|
CONSTANT character_h, 68
|
| 944 |
|
|
CONSTANT character_i, 69
|
| 945 |
|
|
CONSTANT character_j, 6A
|
| 946 |
|
|
CONSTANT character_k, 6B
|
| 947 |
|
|
CONSTANT character_l, 6C
|
| 948 |
|
|
CONSTANT character_m, 6D
|
| 949 |
|
|
CONSTANT character_n, 6E
|
| 950 |
|
|
CONSTANT character_o, 6F
|
| 951 |
|
|
CONSTANT character_p, 70
|
| 952 |
|
|
CONSTANT character_q, 71
|
| 953 |
|
|
CONSTANT character_r, 72
|
| 954 |
|
|
CONSTANT character_s, 73
|
| 955 |
|
|
CONSTANT character_t, 74
|
| 956 |
|
|
CONSTANT character_u, 75
|
| 957 |
|
|
CONSTANT character_v, 76
|
| 958 |
|
|
CONSTANT character_w, 77
|
| 959 |
|
|
CONSTANT character_x, 78
|
| 960 |
|
|
CONSTANT character_y, 79
|
| 961 |
|
|
CONSTANT character_z, 7A
|
| 962 |
|
|
CONSTANT character_A, 41
|
| 963 |
|
|
CONSTANT character_B, 42
|
| 964 |
|
|
CONSTANT character_C, 43
|
| 965 |
|
|
CONSTANT character_D, 44
|
| 966 |
|
|
CONSTANT character_E, 45
|
| 967 |
|
|
CONSTANT character_F, 46
|
| 968 |
|
|
CONSTANT character_G, 47
|
| 969 |
|
|
CONSTANT character_H, 48
|
| 970 |
|
|
CONSTANT character_I, 49
|
| 971 |
|
|
CONSTANT character_J, 4A
|
| 972 |
|
|
CONSTANT character_K, 4B
|
| 973 |
|
|
CONSTANT character_L, 4C
|
| 974 |
|
|
CONSTANT character_M, 4D
|
| 975 |
|
|
CONSTANT character_N, 4E
|
| 976 |
|
|
CONSTANT character_O, 4F
|
| 977 |
|
|
CONSTANT character_P, 50
|
| 978 |
|
|
CONSTANT character_Q, 51
|
| 979 |
|
|
CONSTANT character_R, 52
|
| 980 |
|
|
CONSTANT character_S, 53
|
| 981 |
|
|
CONSTANT character_T, 54
|
| 982 |
|
|
CONSTANT character_U, 55
|
| 983 |
|
|
CONSTANT character_V, 56
|
| 984 |
|
|
CONSTANT character_W, 57
|
| 985 |
|
|
CONSTANT character_X, 58
|
| 986 |
|
|
CONSTANT character_Y, 59
|
| 987 |
|
|
CONSTANT character_Z, 5A
|
| 988 |
|
|
CONSTANT character_0, 30
|
| 989 |
|
|
CONSTANT character_1, 31
|
| 990 |
|
|
CONSTANT character_2, 32
|
| 991 |
|
|
CONSTANT character_3, 33
|
| 992 |
|
|
CONSTANT character_4, 34
|
| 993 |
|
|
CONSTANT character_5, 35
|
| 994 |
|
|
CONSTANT character_6, 36
|
| 995 |
|
|
CONSTANT character_7, 37
|
| 996 |
|
|
CONSTANT character_8, 38
|
| 997 |
|
|
CONSTANT character_9, 39
|
| 998 |
|
|
CONSTANT character_colon, 3A
|
| 999 |
|
|
CONSTANT character_semi_colon, 3B
|
| 1000 |
|
|
CONSTANT character_less_than, 3C
|
| 1001 |
|
|
CONSTANT character_greater_than, 3E
|
| 1002 |
|
|
CONSTANT character_equals, 3D
|
| 1003 |
|
|
CONSTANT character_space, 20
|
| 1004 |
|
|
CONSTANT character_CR, 0D ;carriage return
|
| 1005 |
|
|
CONSTANT character_question, 3F ;'?'
|
| 1006 |
|
|
CONSTANT character_dollar, 24
|
| 1007 |
|
|
CONSTANT character_BS, 08 ;Back Space command character
|
| 1008 |
|
|
;
|
