11
3D GRAPHICS PROCESSING
113
11.5.194
TRXSPOS
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TRXSPOS - Transfer Source Position
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description
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Y Position
0-9
X Position
11.5.195
TRXDPOS
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TRXDPOS - Transfer Destination Position
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TRXSIZE
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TRXSIZE - Transfer Size
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Height = Transfer Height-1
0-9
Width = Transfer Width-1
11.6
Texture Cache
The texture cache is very important on the PSP (as it was on the PS2). From experiments it seems to be 8kB, so that means it’s 64x32
in 32-bit, 64x64 in 16-bit, 128x64 in 8-bit and 128x128 in 4-bit (the sizes are qualified guesses by looking at the PS2). Ordering your
draws so that locality in uv-coordinates is maximized will make sure your rendering is optimal.
DXTn is decompressed into 32-bit when loaded into the cache, so what you gain in shrinking the texture-size, you lose in texture-cache.
If you can, use 4- or 8-bit textures, which will allow a much larger area to be kept in the cache.
11.7
Memory Bandwidth
texture reads from user memory (mem range
0x08800000
-
0x01800000
) have a bandwidth of 50MB/s
texture reads from GE memory or VRAM (mem range
0x04000000
-
0x00200000
) have a bandwidth of 500MB/s
if you have a texture in user memory it is possible to load that texture to VRAM at a bandwidth of 150MB/s
Summary of Contents for PlayStationPortable
Page 114: ...12 AUDIO PROCESSING 114 12 Audio Processing 12 1 Overview 44100 Hz Sample Frequency ...
Page 116: ...14 WLAN 116 14 WLAN ...
Page 117: ...15 USB PORT 117 15 USB Port ...
Page 118: ...16 UMD 118 16 UMD ...
Page 119: ...17 MEMORY STICK 119 17 Memory Stick ...
Page 128: ...21 FLASH MEMORY STRUCTURE FLASH1 128 21 Flash Memory Structure flash1 DIC REGISTRY VSH THEME ...
Page 141: ...28 IPL 141 28 IPL ...
