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Diffstat (limited to 'docs/architecture.md')
| -rw-r--r-- | docs/architecture.md | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/docs/architecture.md b/docs/architecture.md index 7ec0494..6b37604 100644 --- a/docs/architecture.md +++ b/docs/architecture.md @@ -185,7 +185,7 @@ Important notes: for the foreground and background layer, these components will be combined into one for each layer respectively. They are separated in the above diagram for pipeline stage illustration. -- The BAX, FAM, and PAL registers are implemented in the component that +- The AUX, FAM, and PAL registers are implemented in the component that directly accesses them, but are exposed to the PPU RAM bus for writing. - Each foreground sprite render component holds its own sprite data copy from the RAM in it's own cache memory. The cache updates are fetched during the @@ -222,8 +222,6 @@ Important notes: - All DATA and ADDR lines are shared between all RAM ports. WEN inputs are controlled by the address decoder. -<!-- - ## Registers |Address|Size (bytes)|Alias|Description| @@ -232,7 +230,7 @@ Important notes: |`0x00000`|`0x00000`|BAM |[background attribute memory][BAM]| |`0x00000`|`0x00000`|FAM |[foreground attribute memory][FAM]| |`0x00000`|`0x00000`|PAL |[palettes][PAL]| -|`0x00000`|`0x00000`|BAX |[background auxiliary memory][BAX]| +|`0x00000`|`0x00000`|AUX |[auxiliary memory][AUX]| [TMM]: #tilemap-memory ### Tilemap memory @@ -242,24 +240,35 @@ Important notes: [BAM]: #background-attribute-memory ### Background attribute memory +- 15-bit words (padded with 1 bit) +- 11-bit address width (1200 15-bit words with padding 1) + - TODO: list format [FAM]: #foreground-attribute-memory ### Foreground attribute memory +- 2 * 16-bit words +- 8-bit address width (256 16-bit words for 128 * 32-bit) + - TODO: list format [PAL]: #palettes ### Palettes +- 12-bit words +- 6-bit address width (2^6 = 64 colors total) + - TODO: list format -[BAX]: #background-auxiliary-memory -### Background auxiliary memory +[AUX]: #auxiliary-memory +### Auxiliary memory -- background scrolling +- background scrolling (8 + 9 bits) +- fetch foreground sprites bit (1 bit) ---> +- 16-bit words +- 1-bit address width [custompputimings]: https://docs.google.com/spreadsheets/d/1MU6K4c4PtMR_JXIpc3I0ZJdLZNnoFO7G2P3olCz6LSc |