EarthBound/VRAM DMA Transfer Style Table

This is a sub-page of EarthBound.

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 register
• 39: 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