Difference between revisions of "MTX Registers"

From 3dbrew
Jump to navigation Jump to search
(Update MTX bits and interrupts)
 
(One intermediate revision by the same user not shown)
Line 25: Line 25:
 
|-
 
|-
 
| 0x1EC1x00C
 
| 0x1EC1x00C
| ???
+
| [[#MTX_IE|MTX_IE]]
 
| 4
 
| 4
 
|-
 
|-
Line 36: Line 36:
 
==Matrix unit==
 
==Matrix unit==
  
There are two matrix units, one at +0x200, and the other one at +0x300, possibly one for each axis (X and Y)
+
There are two matrix units, one at +0x200 for vertical (Y) scaling, and the other one at +0x300 for horizontal (X) scaling.
  
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
Line 79: Line 79:
 
|-
 
|-
 
| 1
 
| 1
| ??? set after init sequence
+
| Enable vertical matrix
 
|-
 
|-
 
| 2
 
| 2
| ??? set after init sequence
+
| Enable horizontal matrix
 
|-
 
|-
| 3
+
| 4
 
| ???
 
| ???
 
|-
 
|-
| 4
+
| 5
 
| ???
 
| ???
 
|-
 
|-
Line 94: Line 94:
 
|-
 
|-
 
| 10-11
 
| 10-11
| Output pixel mode? Same enum as above.
+
| Output framebuffer rotation: 0 = normal, 1 = 90° CW (right), 2 = 180° CW (upside down, not mirrored), 3 = 270° CW (left)
 
|-
 
|-
 
| 12
 
| 12
| ??? initialized to 0, but if set then requires the output width and height to be multiples of 8
+
| Output tiling for use with the GPU. When set, the output width and height must be a multiple of 8.
 
|-
 
|-
 
| 15
 
| 15
| ??? set after init sequence
+
| Start bit (setting this will eventually raise MTX interrupt 0)
 
|-
 
|-
 
| 16
 
| 16
| ??? not yet inited bit ???
+
| Data still available flag (?)
 
|-
 
|-
 
|}
 
|}
Line 114: Line 114:
 
|-
 
|-
 
| 0-8
 
| 0-8
| Output framebuffer width - 1 is written here
+
| Output framebuffer width - 1 is written here, 1 <= width <= 512
 
|-
 
|-
 
| 16-25
 
| 16-25
| Output framebuffer height - 1 is written here
+
| Output framebuffer height - 1 is written here, 1 <= height <= 512
 
|-
 
|-
 
|}
 
|}
Line 124: Line 124:
  
 
Reading this register will return pending interrupts.
 
Reading this register will return pending interrupts.
Writing this register will acknowledge the pending interrupt.
+
Writing this register will acknowledge pending interrupts where the bits are set.
  
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
Line 131: Line 131:
 
|-
 
|-
 
| 0
 
| 0
| Interrupt 0
+
| FIFO ready (signal to start DMA)
 
|-
 
|-
 
| 1
 
| 1
| Interrupt 1
+
| FIFO overrun(?) (occurs if DMA is too slow)
 
|-
 
|-
 
| 2
 
| 2
| Interrupt 2
+
| FIFO underrun(?) (occurs on VBlank)
 
|-
 
|-
 
|}
 
|}
 +
 +
==MTX_IE==
 +
 +
Interrupt Enable for the above interrupts.

Latest revision as of 01:07, 2 April 2020

These registers are responsible for controlling how framebuffer data can be DMA'd from the DS GPU, and also for configuring the upscaling matrix.

Registers[edit]

The physical address can be calculated by subtracting 0xEB00000 from the virtual address.

Control[edit]

VAddress Name Width
0x1EC1x000 MTX_CNT 4
0x1EC1x004 MTX_SIZE 4
0x1EC1x008 MTX_ACK 4
0x1EC1x00C MTX_IE 4
0x1EC1x020 ??? 4

Matrix unit[edit]

There are two matrix units, one at +0x200 for vertical (Y) scaling, and the other one at +0x300 for horizontal (X) scaling.

VAddress Name Width Description
0x1EC1xn00 KRN_WIDTH 4 Kernel width - 1 is written here, 1 <= width <= 8

This decides how many pixels are written each batch.

0x1EC1xn04 KRN_PATTERN_BITS 4 If the corresponding bit for the current batch iteration index is set then a new pixel is read.

The amount of set bits determine how many pixels are read each batch. Any bit indexes past KRN_WIDTH are ignored.

This value is 8 bits, but it has to be written with a 32bit write.

0x1EC1xn40 KRN_MTX 0xC0 int kerneldata[6][8]; - matrix data is written here, height is always 6

Descriptions[edit]

MTX_CNT[edit]

Bit(s) Description
0 Enable bit
1 Enable vertical matrix
2 Enable horizontal matrix
4 ???
5 ???
8-9 Input pixel mode? 0 = 4byte color, 1 = 3byte color, 2 = 2byte color, 3 = 2byte color
10-11 Output framebuffer rotation: 0 = normal, 1 = 90° CW (right), 2 = 180° CW (upside down, not mirrored), 3 = 270° CW (left)
12 Output tiling for use with the GPU. When set, the output width and height must be a multiple of 8.
15 Start bit (setting this will eventually raise MTX interrupt 0)
16 Data still available flag (?)

MTX_SIZE[edit]

Bit(s) Description
0-8 Output framebuffer width - 1 is written here, 1 <= width <= 512
16-25 Output framebuffer height - 1 is written here, 1 <= height <= 512

MTX_ACK[edit]

Reading this register will return pending interrupts. Writing this register will acknowledge pending interrupts where the bits are set.

Bit(s) Description
0 FIFO ready (signal to start DMA)
1 FIFO overrun(?) (occurs if DMA is too slow)
2 FIFO underrun(?) (occurs on VBlank)

MTX_IE[edit]

Interrupt Enable for the above interrupts.