ceda2vga/src/vga.pio

.program vga_free_run

entrypoint_vga_free_run:
    pull
loop:
    out pins, 1 [2]
    jmp loop

.program vga_hsync

entrypoint_vga_hsync:
    pull
    mov isr, osr
    pull

loope:
    set y, 15
loop:
    mov x, isr
    set pins, 0
hsync_pulse:
    jmp x-- hsync_pulse

    mov x, osr
    set pins, 1
hsync_idle:
    jmp x-- hsync_idle
    jmp y-- loop

    irq set 0
    jmp loope

.program vga_vsync

entrypoint_vga_vsync:
    pull
    mov isr, osr
    pull

loop:
    wait irq 0
    mov x, isr
    set pins, 0
vsync_pulse:
    jmp x-- vsync_pulse

    set pins, 1
    jmp loop