stmd.asm

mega48 microsteeeper基于mega48 步进马达细分程序

spi_stc:     ; SPI transfer complete handler
    ldi     temp1, 18  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
usart_rxc:   ; USART, RX complete handler
    ldi     temp1, 19  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
usart_udre:  ; USART, UDR empty handler
    ldi     temp1, 20  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
usart_txc:   ; USART, TX complete handler
    ldi     temp1, 21  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; *************************************************************************
ADC_com:     ; ADC conversion complete handler
    ldi     temp1, 22  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; *************************************************************************
ee_rdy:      ; EEPROM ready handler
    ldi     temp1, 23  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
ana_comp:    ; analog comparator handler
    ldi     temp1, 24  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
twi:         ; 2-wire serial interface handler
    ldi     temp1, 25  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti


; ************************************************************************
spm_rdy:     ; store program memory ready handler
    ldi     temp1, 26  ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap
    reti

; ************************************************************************
rst:
    ldi r16, high(RAMEND)   
    out SPH,r16             ; set stack pointer to top of RAM
    ldi r16, low(RAMEND)
    out SPL,r16

; ************************************************************************
; configure Port B          ; this port drives the Mx pins of the two LMD18245T driver chips
    ldi temp1,  0b11111111
                ; 1-------  ; 1 = PB7 is ouput, B Driver - M4
                ; -1------  ; 1 = PB6 is ouput, B Driver - M3
                ; --1-----  ; 1 = PB5 is ouput, B Driver - M2
                ; ---1----  ; 1 = PB4 is ouput, B Driver - M1
                ; ----1---  ; 1 = PB3 is ouput, A Driver - M4
                ; -----1--  ; 1 = PB2 is ouput, A Driver - M3
                ; ------1-  ; 1 = PB1 is ouput, A Driver - M2
                ; -------1  ; 1 = PB0 is ouput, A Driver - M1
    out DDRB,   temp1

    ldi temp1,  0b00000000
                ; 0-------  ; 1 = PB7 initially low, B Driver - M4 
                ; -0------  ; 1 = PB6 initially low, B Driver - M3
                ; --0-----  ; 1 = PB5 initially low, B Driver - M2
                ; ---0----  ; 1 = PB4 initially low, B Driver - M1
                ; ----0---  ; 1 = PB3 initially low, A Driver - M4
                ; -----0--  ; 1 = PB2 initially low, A Driver - M3
                ; ------0-  ; 1 = PB1 initially low, A Driver - M2
                ; -------0  ; 1 = PB0 initially low, A Driver - M1
    out PORTB,  temp1

; ************************************************************************
; configure Port C
    ldi temp1,  0b00000000
                ; x-------  ; reserved
                ; -x------  ; PC6 is /Reset, pulled high via 10k
                ; --0-----  ; 0 = PC5 is input, spare input
                ; ---0----  ; 0 = PC4 is input, DIP switch to gnd, test mode select
                ; ----0---  ; 0 = PC3 is input, DIP switch to gnd, disable mode select: Do we let the motors freewheel, or turn braking on?
                ; -----0--  ; 0 = PC2 is input, DIP switch to gnd, step mode select2
                ; ------0-  ; 0 = PC1 is input, DIP switch to gnd, step mode select1
                ; -------0  ; 0 = PC0 is input, DIP switch to gnd, step mode select0
    out DDRC,   temp1

    ldi temp1,  0b01111111
                ; x-------  ; reserved
                ; -1------  ; 1 = PC6 internal pullup enabled
                ; --1-----  ; 1 = PC5 internal pullup enabled
                ; ---1----  ; 1 = PC4 internal pullup enabled
                ; ----1---  ; 1 = PC3 internal pullup enabled
                ; -----1--  ; 1 = PC2 internal pullup enabled
                ; ------1-  ; 1 = PC1 internal pullup enabled
                ; -------1  ; 1 = PC0 internal pullup enabled
    out PORTC,  temp1

; ************************************************************************
; configure Port D
    ldi temp1,  0b11100011  
                ; 1-------  ; 1 = PD7 is output, idle current reduction enable, 1k0 resistor to DAC_REF pins on drivers.
                            ;                    DAC_REF pins on drivers are pulled high thru 1k0, so bringing this pin low
                            ;                    sets up a voltage divider, thereby reducing the DAC_REF voltage
                ; -1------  ; 1 = PD6 is output, motor brake control, connects to BRAKE pins on drives thru a removeable jumper, goes high to turn braking on
                ; --1-----  ; 1 = PD5 is output, aliveLED to gnd thru 470R, toggles on a 500mS basis
                ; ---0----  ; 0 = PD4 is input, enable input from opto-isolator, pulled high through 270R, goes low when 5v is applied to input of opto-isolator
                ; ----0---  ; 0 = PD3 is input, direction input from opto-isolator, pulled high through 270R, goes low when 5v is applied to input of opto-isolator
                ; -----0--  ; 0 = PD2 is input, step input from opto-isolator, pulled high through 270R, goes low when 5v is applied to input of opto-isolator
                ; ------1-  ; 1 = PD1 is output, goes to B driver - Dir pin
                ; -------1  ; 1 = PD0 is output, goes to A Driver - Dir pin
    out DDRD,  temp1

    ldi temp1,  0b10011100
                ; 1-------  ; 1 = idle current reduction initially off
                ; -0------  ; 0 = motor braking initially off
                ; --0-----  ; 0 = aliveLED initially off
                ; ---111--  ; 111 = enable internal pull-ups for optically isolated inputs
                ; ------00  ; 0 = DIR pins on A & B drivers is initially low
    out PORTD,  temp1

; ************************************************************************
; check MCUSR for source of reset
; only power-on reset flag is valid
; all others are trapped

    in      temp1, MCUSR
    sbrc    temp1, PORF     ; power-on reset?
    rjmp    continue

wd_reset:
    sbrs    temp1, WDRF     ; watchdog reset?
    rjmp    brout_reset
    ldi     temp1, 27       ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap

brout_reset:    
    sbrs    temp1, BORF     ; brownout reset?
    rjmp    ext_reset
    ldi     temp1, 28       ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap

ext_reset: 
    sbrs    temp1, EXTRF    ; external reset?
    rjmp    continue
    ldi     temp1, 29       ; fault code
    mov     fault_code, temp1
    rjmp    fault_trap

continue:

; ************************************************************************
; configure timer/counter0  ; we will use timer0 to toggle aliveLED on a 500 ms basis
    ldi temp1,  0b00000000
                ; 00------  ; 00 = normal port operation, OC0A disconnected
                ; --00----  ; 00 = normal port operation, OC0B disconnected
                ; ----xx--  ; reserved
                ; ------00  ; 00 = normal waveform generation mode
    out TCCR0A, temp1

    ldi temp1,  0b00000100
                ; 0-------  ; 1 = force output compare for channel A
                ; -0------  ; 1 = force output compare for channel B
                ; --xx----  ; reserved
                ; ----0---  ; 0 = normal waveform generation mode
                ; -----000  ; 000 = disabled
                ; -----001  ; 001 = no prescaler, internal clock
                ; -----011  ; 011 = 1:64 prescaler, internal clock
                ; -----100  ; 100 = 1:256 prescaler, internal clock
                ; -----101  ; 101 = 1:1024 prescaler, internal clock
    out TCCR0B, temp1

    clr temp1               ; clear some registers
    out TCNT0, temp1
    out OCR0A, temp1
    out OCR0B, temp1

    ; 8Mhz clock -> 125 ns instruction cycle
    ; 8 bit counter, 2^8 x 125 ns = 32 us
    ; with 1:256 prescaler: 256 x 32 us = 8.192 ms per rollover
    ; for 500 ms delay: 500 ms / 8.192 ms = 61.03 rollovers per 500 ms
    ; -- calculate error for 61 rollovers: 61 * 8.192 ms = 499.712 ms 
    ; --- close enough for toggling a LED!!!!
    .equ tim0_LEDrolls_target = 61
    ldi tim0_LEDrolls, 0

; enable/disable timer/counter0 interrupts
    ldi temp1,  0b00000001
                ; xxxxx---  ; reserved
                ; -----0--  ; 0 = timer/counter0 Output Compare B Match interrupt disabled
                ; ------0-  ; 0 = timer/counter0 Output Compare A Match interrupt disabled
                ; -------0  ; 0 = timer/counter0 Overflow interrupt disabled
    sts TIMSK0, temp1

; ************************************************************************
; configure timer/counter1  ; use OC1A to generate timed steps for test mode
    ldi temp1,  0b00000000
                ; 00------  ; normal port operation, OC1A disconnected
                ; --00----  ; normal port operation, OC1B disconnected
                ; ----xx--  ; reserved
                ; ------00  ; 00 = clear timer on compare match with OCR1A
                ; ------00  ; 00 = clear timer on compare match with ICR1
                ; ------00  ; 00 = normal mode
    sts TCCR1A, temp1

    ldi temp1,  0b00001001
                ; 0-------  ; 0 = input capture noise canceler disabled
                ; -0------  ; 0 = trigger capture on falling edge of IC1
                ; --x-----  ; reserved
                ; ---00---  ; 00 = normal mode
                ; ---01---  ; 01 = clear timer on compare match with OCR1A
                ; ---11---  ; 11 = clear timer on compare match with ICR1
                ; -----001  ; 001 = no prescaler, internal clock
                ; -----011  ; 011 = 1:64 prescaler, internal clock
    sts TCCR1B, temp1

    ldi temp1,  0b00000000
                ; 0-------  ; 1 = force output compare for channel A
                ; -0------  ; 1 = force output compare for channel B
                ; --xxxxxx  ; reserved
    sts TCCR1C, temp1
    
    clr temp1               ; clear some registers
    clr temp2         
    sts TCNT1H, temp1       
    sts TCNT1L, temp2
    
    clr temp1               ; clear some registers
    clr temp2         
    sts OCR1AH, temp1       
    sts OCR1AL, temp2
    
    clr temp1               ; clear some registers
    clr temp2         
    sts OCR1BH, temp1       
    sts OCR1BL, temp2
    
; enable/disable timer/counter1 interrupts
    ldi temp1,  0b00000000
                ; --0-----  ; 0 = input capture interrupt disabled
                ; xx-xx---  ; reserved
                ; -----0--  ; 0 = timer/counter2 Output Compare B Match interrupt disabled
                ; ------0-  ; 0 = timer/counter2 Output Compare A Match interrupt disabled
                ; -------0  ; 0 = timer/counter2 Overflow interrupt disabled
    sts TIMSK1, temp1

; ************************************************************************
; configure timer/counter2  ; we will use timer2 enable idle current reduction after 3 seconds of no step activity
    ldi temp1,  0b00000000
                ; 00------  ; 00 = normal port operation, OC0A disconnected
                ; --00----  ; 00 = normal port operation, OC0B disconnected
                ; ----xx--  ; reserved
                ; ------00  ; 00 = normal waveform generation mode
    sts TCCR2A, temp1

    ldi temp1,  0b00000111
                ; 0-------  ; 1 = force output compare for channel A
                ; -0------  ; 1 = force output compare for channel B
                ; --xx----  ; reserved
                ; ----0---  ; 0 = normal waveform generation mode
                ; -----000  ; 000 = disabled