penguin86/pato-z80-home-computer
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

New test pattern, still hsync issues

Browse Source
This commit is contained in:
Daniele Verducci su MatissePenguin 2021-01-03 12:48:38 +01:00
parent 08b32b2064
commit c0f7049df9
1 changed files with 24 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
pat80-io-devices/composite-pal-adapter/software/avr-assembly/main.asm
View File

@ -38,30 +38,15 @@ v_refresh_loop:
h_picture_outer_loop: h_picture_outer_loop:
ldi r17, 152 ; line counter ldi r17, 152 ; line counter
h_picture_loop: h_picture_loop:
; start line sync: 4uS, 96 cycles @ 24Mhz call line_sync
cbi PORTD, SYNC_PIN ; sync goes low (0v) ; 2 cycle
ldi r18, 32 ; 1 cycle
l_sync_pulse_loop: ; requires 3 cpu cycles
dec r18 ; 1 cycle
brne l_sync_pulse_loop ; 2 cycle if true, 1 if false
sbi PORTD, SYNC_PIN ; sync goes high (0.3v)
; end line sync
; start back porch: 8uS, 192 cycles @ 24Mhz
ldi r18, 64 ; 1 cycle
l_sync_back_porch_loop:
dec r18 ; 1 cycle
brne l_sync_back_porch_loop ; 2 cycle if true, 1 if false
; end back porch
; start image: 52uS, 1247 cycles @ 24Mhz ; start image: 52uS, 1247 cycles @ 24Mhz
; 3 bande da 416 cicli ; 3 bande da 416 cicli
sbi PORTD, VIDEO_PIN ; video goes high ; 2 cycle ldi r18, 59 ; 1 cycle
ldi r18, 138 ; 1 cycle
l_sync_video_loop1: l_sync_video_loop1:
sbi PORTD, VIDEO_PIN ; video goes high ; 2 cycle
dec r18 ; 1 cycle dec r18 ; 1 cycle
cbi PORTD, VIDEO_PIN ; video goes low ; 2 cycle
brne l_sync_video_loop1 ; 2 cycle if true, 1 if false brne l_sync_video_loop1 ; 2 cycle if true, 1 if false
cbi PORTD, VIDEO_PIN ; video goes low cbi PORTD, VIDEO_PIN ; video goes low
@ -139,4 +124,24 @@ short_sync:
dec r18 ; 1 cycle dec r18 ; 1 cycle
brne short_sync_high_loop ; 2 cycle if true, 1 if false brne short_sync_high_loop ; 2 cycle if true, 1 if false
ret
line_sync:
; line sync & front porch
; start line sync: 4uS, 96 cycles @ 24Mhz
cbi PORTD, SYNC_PIN ; sync goes low (0v) ; 2 cycle
ldi r18, 32 ; 1 cycle
l_sync_pulse_loop: ; requires 3 cpu cycles
dec r18 ; 1 cycle
brne l_sync_pulse_loop ; 2 cycle if true, 1 if false
sbi PORTD, SYNC_PIN ; sync goes high (0.3v)
; end line sync
; start back porch: 8uS, 192 cycles @ 24Mhz
ldi r18, 64 ; 1 cycle
l_sync_back_porch_loop:
dec r18 ; 1 cycle
brne l_sync_back_porch_loop ; 2 cycle if true, 1 if false
; end back porch
ret ret