+=-=-=-=-=-=-=-=-=-=-=+ | SNES Memory Mapping | | By: ]SiMKiN[ | | v1.0 | +=-=-=-=-=-=-=-=-=-=-=+ • LoROM: Mode 20 • HiROM: Mode 21 • FastROM's can execute at 3.58Mhz • SlowROM's can only execute 2.68Mhz • The SNES lets you access ROM through bank $00 onwards and bank $80 onwards such that locations $00:8000 and $80:8000 are congruent, (they access the same locations.) • When accessing bank $00 onwards the 65816 runs at 2.68Mhz. However, when accessing bank $80 onwards the 65816 can run at 2.68Mhz or 3.58Mhz depending on how you set bit 0 of $420D. +=========+=============+====================================+=========+ | Bank | Offset | Definition | Shadow | +=========+=============+====================================+=========+ | $00-$2f | $0000-$1fff | LowRAM, each bank is shadowed | $00-$3f | | | | From bank $7e | $7e | | | $2000-$2fff | PPU1, APU | $00-$3f | | | $3000-$3fff | SFX, DSP, etc. | $00-$3f | | | $4000-$41ff | Controller | $00-$3f | | | $4200-$5fff | PPU2, DMA, etc. | $00-$3f | | | $6000-$7fff | Reserved? | $00-$3f | | | $8000-$ffff | (Mode 20, 21 - ROM) | ------- | +---------+-------------+------------------------------------+---------+ | $30-$3f | $0000-$1fff | LowRAM, each bank is shadowed | $00-$3f | | | | From bank $7e | $7e | | | $2000-$2fff | PPU1, APU | $00-$3f | | | $3000-$3fff | SFX, DSP, etc. | $00-$3f | | | $4000-$41ff | Controller | $00-$3f | | | $4200-$5fff | PPU2, DMA, etc. | $00-$3f | | | $6000-$7fff | (Mode 21 - SRAM) 256KBytes | ------- | | | $8000-$ffff | (Mode 20, 21 - ROM) | ------- | +---------+-------------+------------------------------------+---------+ | $40-$6f | $0000-$7fff | (Mode 21 - ROM) | ------- | | | $8000-$ffff | (Mode 20, 21 - ROM) | ------- | +---------+-------------+------------------------------------+---------+ | $70-$77 | $0000-$ffff | (Mode 20, 21 - SRAM) 256KBytes | ------- | +---------+-------------+------------------------------------+---------+ | $78-$7d | $0000-$ffff | Never Used | ------- | +---------+-------------+------------------------------------+---------+ | $7e | $0000-$1fff | LowRAM | $00-$3f | | | | Shadowed to banks $00-$3f | ------- | | | $2000-$7fff | HighRAM | ------- | | | $8000-$ffff | Expanded Ram | ------- | +---------+-------------+------------------------------------+---------+ | $7f | $0000-$ffff | More Expanded RAM | ------- | +---------+-------------+------------------------------------+---------+ | $80-$ef | $0000-$ffff | Mirror of $00-$6f | $00-$6f | +---------+-------------+------------------------------------+---------+ | $f0-$ff | $0000-$ffff | (Mode 21 - ROM) | ------- | +=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+ • ROM: The SNES ROM Image • RAM: The SNES Work Memory (WRAM) LowRAM, HighRAM, & Expanded RAM All together = 128 Kilo-Bytes • SRAM: Save RAM (Extra RAM added by Cart) The SNES only utilizes 256 Kilo-bits However 256 Kilo-Bytes are provided. • APU: Audio Processing Unit SPC700, Inside which has a DSP • PPU: Picture Processing Unit PPU1: 5c77-01 PPU2: 5c78-03 • SFX: Super FX Cart Chip, by Nintendo • DSP: Digital Signal Processing Cart Chip a.k.a. 'NEC mUPD77C25' • Shadow: "Congruent Bank". Same meaning as Mirror. _________________________________________________ .o(_Thanx to: Y0SHi, zsKnight, MrGrim, and MintaBoo_)o.