23
edits
Changes
→LCD Source Framebuffer Setup: Correct typo in mathematical calculation.
! Name
! Name
! Comments
! Comments
|-
| 0x1EF00000
| 0x10400000
| 4
| Hardware ID
| Bit2: new model
|-
|-
| 0x1EF00004
| 0x1EF00004
| 4
| 4
| VRAM bank control
| VRAM bank control
| Bits 8-11 = bank[i] disabled; other bits are unused
| Bits 8-11 = bank[i] disabled; other bits are unused.
|-
|-
| 0x1EF00034
| 0x1EF00034
| 4
| 4
| GPU Busy
| GPU Busy
| Bit31 = cmd-list busy, bit27 = PSC0 busy, bit26 = PSC1 busy.
| Bit26 = PSC0, bit27 = PSC1, Bit30 = PPF, Bit31 = P3D
|-
|-
| 0x1EF00050
| 0x1EF00050
All pixel and scanline timing values are 12bits, unless noted. This also applies to those fields where two u16 are combined into one register. Each u16 field is only 12bits in size. timin
All pixel and scanline timing values are 12bits, unless noted. This also applies to those fields where two u16 are combined into one register. Each u16 field is only 12bits in size. timin
The horizontal timing parameter order is as follows:
The horizontal timing parameter order is as follows (values may overflow through HTotal register value):
0x10 --> 0x14 --> 0x18 --> 0x60 low --> 0x04 --> 0x60 high --> 0x08 --> 0x0C.
0x10 < 0x14 <= 0x60.LO <= 0x04 <= 0x60.HI <= 0x08 <= 0x0C <= 0x10
0x18 <= 0x60.LO
Timing starts from HCount == 0, then each absolute value in the beforementioned register chain triggers when HCount == register, latching the primitive display controller into a new mode.
Timing starts from HCount == 0, then each absolute value in the beforementioned register chain triggers when HCount == register, latching the primitive display controller into a new mode.
There is an inherent latch order, where if two simultenaous events occur, one event wins over another.
There is an inherent latch order, where if two simultenaous events occur, one event wins over another.
Known latched modes (in no particular order):
Known latched modes (in order):
- HSync (triggers a line to the LCD to move to the next line)
- HSync (triggers a line to the LCD to move to the next line)
- Back porch (area between HSync and border being displayed)
- Back porch (area between HSync and border being displayed, no pixels pushed, min 16 pixel clocks, otherwise the screen gets glitchy)
- Left border start (no image data is being displayed, just a configurable solid color)
- Left border start (no image data is being displayed, just a configurable solid color)
- Image start (pixel data is being DMA'd from video memory or main RAM)
- Image start (pixel data is being DMA'd from video memory or main RAM)
- Right border start/Image end (border color is being displayed after the main image)
- Right border start/Image end (border color is being displayed after the main image)
- Front porch (unknown where it happens)
- Unknown synchronization (supposed to be probably right border end, but this mode seems to be broken or not do anything)
- Unknown synchronization/blanking (unknown where it happens)
- Front porch (no pixels pushed, 68 clock min, otherwise the screen doesn't sync properly, and really glitches out)
{| class="wikitable" border="1"
{| class="wikitable" border="1"
|-
|-
| 0x04
| 0x04
| HParam5
| HStart
|
| Determines when the image is going to be displayed in the visible region (register 0x60).
|-
|-
| 0x08
| 0x08
| HParam7
| HBR
| Right border start(?). Does nothing.
While this register seems to have no impact on the image whatsoever, it still has to be set to a valid value.
|
|
|-
|-
| 0x0C
| 0x0C
| HParam8
| HPF
|
| Front porch. The image is blanked during this period, and no pixels are pushed to the LCD.
Unknown why, but a single dot of red is displayed before entering this mode.
|-
|-
| 0x10
| 0x10
| HParam1
| HSync
|
| Triggers a HSync pulse.
Based on behavior, this needs to last at least a pixel clock for the LCD to register the sync.
|-
|-
| 0x14
| 0x14
| HParam2
| HPB
|
| Back porch? Has to be at least one bigger than HSync, otherwise HSync never triggers.
The display is blank, and the LCD displays nothing in this period (doesn't push pixels).
|-
|-
| 0x18
| 0x18
| HParam3
| HBL
|
| Left border trigger treshold. Enables pushing pixels to the display.
If this value is smaller than the back porch, then the back porch period will be zero, and the border will be immediately displayed upon entering the back porch period.
Can be lower than HSync, as the back porch is what takes the controller out of HSync.
Must be <= HDisp start (reg 0x60 low u16), otherwise no pixels will be pushed due to a glitched state.
|-
|-
| 0x1C
| 0x1C
VClock = PClock / (HTotal + 1) / (VTotal + 1)
VClock = PClock / (HTotal + 1) / (VTotal + 1)
Setting this to 494 lowers framerate to about 50.040660858 Hz ((268111856 / 24) / (250 + 1) / (494 + 1)).
Setting this to 494 lowers framerate to about 50.040660858 Hz ((268111856 / 24) / (450 + 1) / (494 + 1)).
|-
|-
| 0x28
| 0x28
|-
|-
| 0x60
| 0x60
| ???
| HDisp
| low u16: HParam4
| low u16: Image start (border --> pixel data)
high u16: HParam6
high u16: Image end (pixel data --> border)
|-
|-
| 0x64
| 0x64
| 0x70
| 0x70
| Framebuffer format and other settings
| Framebuffer format and other settings
| Bit 0-2: framebuffer format
| See [[#Framebuffer_format|framebuffer format]]
|-
|-
| 0x74
| 0x74
|-
|-
| 2-0
| 2-0
| Color format
| [[#Framebuffer_color_formats|Color format]]
|-
|-
| 5-4
| 5-4
| Framebuffer scanline output mode (interlace config)
| Framebuffer scanline output mode (framebuffer interleave config)
0 - A (output image as normal)
0 - A (output image as normal)
1 - AA (output a single line twice, aka framebuffer A is interlaced with itself)
1 - AA (output a single line twice, so framebuffer A is interleaved with itself)
2 - AB (interlace framebuffer A and framebuffer B)
2 - AB (interleave framebuffer A and framebuffer B)
3 - BA (same as above, but the line from framebuffer B is outputted first)
3 - BA (same as above, but the line from framebuffer B is outputted first)
|-
|-
| 9-8
| 9-8
| Value 1 = unknown: get rid of rainbow strip on top of screen, 3 = unknown: black screen.
| DMA size
0 - 4 words (32 bytes)
1 - 8 words (64 bytes)
2 - 16 words (128 bytes)
3 - ???
FCRAM doesn't support DMA size 3, as it can only burst up to 16 words (128 bytes), and will show a black screen instead.
|-
|-
| 15-10
| 31-16
| Unused?
| Unknown
|}
|}