HuC6280The HuC6280 processor provides a 21bit address bus on the TurboGrafx allowing contiguous addressing of up to 2MB. The address space is divided into 256 8KB pages.
| Start Address | End Address | Pages | Size* | Description | | 0x000000 | 0x0FFFFF | 0x00 - 0x7F | 1MB | HuCard ROM Space (may be mirrored with HuCards smaller than 1MB) | | 0x100000 | 0x1EEFFF | 0x80 - 0xF7 | | Unused, see CD-ROM info | | 0x1F0000 | 0x1F7FFF | 0xF8 - 0xFB | 8KB | RAM - pages 0xF9 - 0xFB are mirrors of 0xF8 | | 0x1F8000 | 0x1FDFFF | 0xFC - 0xFE | | Unused | | 0x1FE000 | 0x1FFFFF | 0xFF | 8KB | Hardware Page |
*size refers to the useful size within the range, excluding any mirroring
| Start Address | End Address | Pages | Size* | Description | | 0x000000 | 0x0CFFFF | 0x00 - 0x67 | 832KB | ROM Space | | 0x0D0000 | 0x0FFFFF | 0x68 - 0x7F | 192KB | RAM |
Hardware Page| Start Address | End Address | Description | | 0x0000 | 0x03FF | Video Display Controller - mirrored every 4 bytes | | 0x0400 | 0x07FF | Video Colour Encoder - mirrored every 8 bytes | | 0x0800 | 0x0BFF | Programmable Sound Generator | | 0x0C00 | 0x0FFF | Timer - mirrored every 2 bytes | | 0x1000 | 0x17FF | I/O Port - mirrored every byte | | 0x1400 | 0x17FF | Interrupt control - mirrored every 4 bytes | | 0x1800 | 0x1BFF | See CD-ROM info | | 0x1C00 | 0x1FFF | Unused - always returns 0xFF |
CD-ROMThe TurboGrafx-CD consists of the following memory: - 64KB RAM
- 64KB ADPCM RAM
- 2KB Battery-backed RAM
| Start Address | End Address | Pages | Size* | Description | | 0x100000 | 0x10FFFF | 0x80 - 0x87 | 64KB | CD RAM | | 0x1EE000 | 0x1EE7FF | 0xF7 | 2KB | Battery-backed RAM |
CD-ROM Registers| Address | Page | Description | | 0x1800 | 0xFF | CDC Status | | 0x1801 | 0xFF | CDC Command / Status / Data | | 0x1802 | 0xFF | ADPCM / CD Control | | 0x1803 | 0xFF | BRAM Lock / CD Status | | 0x1804 | 0xFF | CD Reset | | 0x1805 | 0xFF | Convert PCM Data / PCM Data | | 0x1806 | 0xFF | PCM Data | | 0x1807 | 0xFF | BRAM Unlock / CD Status | | 0x1808 | 0xFF | ADPCM Address (LSB) / CD Data | | 0x1809 | 0xFF | ADPCM Address (MSB) | | 0x180A | 0xFF | ADPCM RAM Data Port | | 0x180B | 0xFF | ADPCM DMA Control | | 0x180C | 0xFF | ADPCM Status | | 0x180D | 0xFF | ADPCM Address Control | | 0x180E | 0xFF | ADPCM Playback Rate | | 0x180F | 0xFF | ADPCM and CD Audio Fade Timer |
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