; Copyright (c) 2023 - 2025 kio@little-bat.de
; BSD-2-Clause license
; https://opensource.org/licenses/BSD-2-Clause


.program scanline_vga	; version without clocks (what you normally need)
 
.side_set 0				; no signals
.define CLK 0			; no pixel clock
.define DEN 0			; no data enable 

.define BPP 16			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap 


.program scanline_den	; version with clock & den (for parallel LCD)
 
.side_set 2				; 2 signals
.define CLK 1			; pixel clock
.define DEN 2			; data enable 

.define BPP 16			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap 


.program scanline_clk	; version with clock but no den
 
.side_set 1				; 1 signal
.define CLK 1			; pixel clock
.define DEN 0			; no data enable 

.define BPP 16			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap 


.program scanline_vga_8bpp	; version without clocks (what you normally need)
 
.side_set 0				; no signals
.define CLK 0			; no pixel clock
.define DEN 0			; no data enable 

.define BPP 8			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap 


.program scanline_den_8bpp	; version with clock & den (for parallel LCD)
 
.side_set 2				; 2 signals
.define CLK 1			; pixel clock
.define DEN 2			; data enable 

.define BPP 8			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap 


.program scanline_clk_8bpp	; version with clock but no den
 
.side_set 1				; 1 signal
.define CLK 1			; pixel clock
.define DEN 0			; no data enable 

.define BPP 8			; BPP must be 2^N and num_pixels*BPP % 32 must be 0

		out y, 32		side 0			; read num_pixels-1    note could use EXEC_CMD
.wrap_target 
		wait irq, 4		side 0			; wait for trigger by timing_sm
		mov x, y		side DEN		; reload count. also delays 1cc after wait as in original scanvideo code
loop:
		out  pins, BPP	side DEN		; output pixel
		jmp  x-- loop	side (DEN+CLK)	; loop. also delays 1cc.
		mov pins, null	side DEN		; black
.wrap