; port functions

PORT_INIT:

	; port b 0-3 -> output
	ldi tmp1,0x0f
	out DDRB,tmp1

	; disable hc595 outputs
	sbi PORTB,0

	; rck -> low
	cbi PORTB,1

	; clear hc595 registers
	cbi PORTB,3

	; rck -> high (store shift register data)
	sbi PORTB,1

	; enable outputs
	cbi PORTB,0

	; port d 6 -> output
	sbi DDRD,6

	; ser -> low
	cbi PORTD,6

	; port d 2 -> output (debug clk!)
	sbi DDRD,2

	; port d 3 -> output (debug vertical!)
	sbi DDRD,3

	; release hc595 register clear
	sbi PORTB,3

	ret

SET_HC595:

	; storage clock -> low
	cbi PORTB,1

	; zero to everything ...
	cbi PORTB,3 ; clear hc595 registers
	sbi PORTB,1 ; store shift register data
	cbi PORTB,1 ; release hc595 register clear
	sbi PORTB,3 ; storage clock -> low

	; source driver

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,0
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,0
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,1
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,1
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,2
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,2
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,3
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,3
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,4
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,4
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,5
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,5
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,6
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,6
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_source,7
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_source,7
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2

	; sink driver
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,7
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,7
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,6
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,6
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,5
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,5
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,4
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,4
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,3
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,3
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,2
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,2
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,1
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,1
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; clock -> low
	cbi PORTB,2
	; set ser line
	cbi PORTD,6
	sbrc hc595_sink,0
	sbi PORTD,6
.ifdef DEBUG_PORTS
	ldi uart_rxtx,0x30
	sbrc hc595_sink,0
	ldi uart_rxtx,0x31
	rcall UART_TX
.endif
	; clock -> high
	sbi PORTB,2
	
	; store to storage register
	sbi PORTB,1

	ret