Module board 

The Board trait — the SNES analogue of RustyNES’s Mapper.

A “board” is one cartridge PCB family: a base address-mapping mode (LoROM / HiROM / ExHiROM) plus any on-cart coprocessor. The 65C816 bus calls Board::read24 / Board::write24 with a full 24-bit (bank << 16) | addr; the board decodes its own mapping. Coprocessor boards additionally implement the default-no-op hooks (Board::coprocessor_tick, the notify_* family) — exactly the RustyNES pattern where per-board IRQ/cycle quirks live INSIDE the board, called via default-no-op trait hooks.

See docs/cart.md for the per-board / per-coprocessor table and the decode formulas.

Structs

ExHiRom

ExHiROM (mode $25): the extended HiROM layout for >4 MiB titles.

ExLoRom

ExLoROM (unofficial — no dedicated $xFD5 mode value): the extended LoROM layout for titles over 4 MiB that keep LoROM’s 32 KiB bank windowing instead of switching to HiROM’s linear banks.

HiRom

HiROM (mode $21): 64 KiB linear ROM banks; full ROM at $C0–$FF.

LoRom

LoROM (mode $20): 32 KiB ROM windows in $8000–$FFFF of each bank.

Enums

MappedAddr

The result of a board’s address decode: where a 24-bit CPU address lands.

Traits

Board

A cartridge board: its address mapping + any coprocessor behavior.

Functions

select

Select the concrete board for a parsed header, allocating ROM + zeroed SRAM.

Type Aliases

Coprocessor

Identifies which coprocessor (if any) a board carries.