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EarthBound/VRAM DMA Transfer Style Table
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| VRAM DMA Transfer Style Table | |
| Game | EarthBound |
| Start Address | 0x0091B0 |
| End Address | 0x0091E5 |
| # of Entries | 18 |
| Entry Length | 3 bytes (0x03) |
| Total Length | 54 bytes (0x36) |
| Back to the ROM map | |
The VRAM DMA Transfer Style Table stores miscellaneous parameters for DMA transfers to/from VRAM.
Format
DMA Parameters
- Length: 1 byte (0x1)
- Offset within entry: 0x00
- Range of values: 0x00-0xFF
Value to be copied into the DMA Parameters register. Controls the DMA transfer pattern and direction.
DMA B-Bus Address
- Length: 1 byte (0x1)
- Offset within entry: 0x01
- Range of values: 0x18,0x19,0x39,0x3a (VRAM read/write registers)
Value to be copied into the DMA B-Bus Address register. Interpreted as an address within the $0021xx range.
Valid values for VRAM transfers:
18: VRAM Write Low register (also used when targeting both VRAM Write Low and VRAM Write High registers)19: VRAM Write High register39: VRAM Read Low register (also used when targeting both VRAM Read Low and VRAM Read High registers)3a: VRAM Read High register
VRAM Address Increment
- Length: 1 byte (0x1)
- Offset within entry: 0x02
- Range of values: 0x00-0xFF
Value to be copied into the VRAM Address Increment (VMAIN) register. Controls VRAM address increment and mapping for the transfer.
Table Contents
| Offset | Value | Description |
|---|---|---|
| 00 | 011880 | Memory -> VRAM |
| 03 | 091880 | Fixed address -> VRAM |
| 06 | 001800 | Memory -> low-byte-only VRAM (e.g. for Mode 7) |
| 09 | 081800 | Fixed address -> low-byte-only VRAM |
| 0C | 001980 | Memory -> high-byte-only VRAM |
| 0F | 081980 | Fixed address -> high-byte-only VRAM |
| 12 | 813980 | VRAM -> memory |
| 15 | 803900 | Low-byte-only VRAM -> memory |
| 18 | 803a80 | High-byte-only VRAM -> memory |
| 1B | 011881 | Memory -> VRAM, incrementing VRAM 32 words after each write |
| 1E | 091881 | Fixed address -> VRAM, incrementing 32 words |
| 21 | 001801 | Memory -> low-byte-only VRAM, incrementing 32 words |
| 24 | 081801 | Fixed address -> low-byte-only VRAM, incrementing 32 words |
| 27 | 001981 | Memory -> high-byte-only VRAM, incrementing 32 words |
| 2A | 081981 | Fixed address -> high-byte-only VRAM, incrementing 32 words |
| 2D | 813981 | VRAM -> memory, incrementing VRAM 32 words |
| 30 | 803901 | Low-byte-only VRAM -> memory, incrementing VRAM 32 words |
| 33 | 803a81 | High-byte-only VRAM -> memory, incrementing VRAM 32 words |