fceux/documentation/tech/exp/mmc5-e.txt

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========= mmc5 infomation ==========
date 1998/05/31
by goroh
translated May 31, 1998 by Sgt. Bowhack
mail goroh_kun@geocities.co.jp
5000,5004 ch1,ch2 Pulse Control
bit CCwevvvv
CC Duty Cycle (Positive vs. Negative)
#0:87.5% #1:75.0% #2:50.0% #3:25.0%
w Waveform Hold (e.g. Looping)
0: Off 1: On
e Envelope Select
0: Varied 1: Fixed
< e=0 >
vvvv Playback Rate
#0<-fast<--->-slow--> #15
< e=1 >
vvvv Output Volume
5002,5006 ch1,ch2 frequency L
bit ffffffff
5003,5007 ch1,ch2 frequency H
bit tttttfff
ttttt sound occurence time
Objective is to remove the continuous changing of frequency for
square wave setup and do the same to the main part of the square wave
of studying the main part of the famicom. (?- Sgt. Bowhack)
5010 ch3 synthetic voice business channel
bit -------O
O wave output 0:Off 1:On
5011 ch4 synthetic voice business channel 2
bit vvvvvvvv
vvvvvvvv wave size
5015 sound output channel
bit ------BA
A: ch1 output 1:enable 0:disable
B: ch2 output 1:enable 0:disable
5100 PRG-page size Setting
bit ------SS
SS PRG-page size
0: 32k 1:16k 2,3:8k
* Reset is misled the first times for about 8k (?- SB)
5101 CHR-page size Setting
bit ------SS
SS CHR-page size
0:8k 1:4k 2:2k 3:1k
5102 W BBR-RAM Write Protect 1
bit ------AA
5103 W BBR-RAM Write Protect 2
bit ------BB
(AA,BB) = (2,1) permitted to write to BBR-RAM only when crowded
*Reset write around becomes prohibited when crowded
5104 Grafix Mode Setting
$5c00-$5fff decides how it should be used
bit ------MM
#00:Enable only Split Mode
#01:Enable Split Mode & ExGrafix Mode
#02:ExRAM Mode
#03:ExRAM Mode & Write Protect
Consideration
MMC5 has 2 graphic mode extensions that allow more than 256 characters
on one standard game screen. It uses Split Mode so it can display the
specified CHR-page and scroll position seperate from ExGrafix Mode to
be able to choose a palette, and the other divides it vertically.
5105 W NameTable Setting
bit ddccbbaa
aa: Select VRAM at 0x2000-0x23ff
bb: Select VRAM at 0x2400-0x27ff
cc: Select VRAM at 0x2800-0x2bff
dd: Select VRAM at 0x2c00-0x2fff
#0:use VRAM 0x000-0x3ff
#1:use VRAM 0x400-0x7ff
#2:use ExVRAM 0x000-0x3ff
#3:use ExNameTable(Fill Mode)
Consideration
The name table can designate 4 kinds of this resister and be a useful
special quality for this because painting and smashing it with a
character that there is 1 sheet for the remaining sheets can generally
be used. (?-SB)
5106 W Fill Mode Setting 1
bit vvvvvvvv
Fill chr-table
For whether it paints or smashes it at any non-designated character
5107 W Fill Mode Setting 2
bit ------pp
Whether or not it uses any non-designated palettes
5113 RAM-page for $6000-$7FFF
bit -----p--
5114-5117 Program Bank switch
< page_size=32k >
$5117 [8]-[F] bit pppppp--
< page_size=16k >
$5115 [8]-[B] bit ppppppp-
$5117 [C]-[F] bit ppppppp-
< page_size=8k >
$5114 [8][9] bit pppppppp
$5115 [A][B] bit pppppppp
$5116 [C][D] bit pppppppp
$5117* [E][F] bit pppppppp
*Reset is around early, Last Page misled
5120-512b Charactor Bank switch
< page_size=8k >
$5120-$5127 switch to mode A
$5128-$512b switch to mode B
$5127 [0]-[7] modeA
$512b [0]-[7] modeB
< page_size=4k >
$5120-$5127 switch to mode A
$5128-$512b switch to mode B
$5123 [0]-[3] modeA
$5127 [4]-[7] modeA
$512b [0]-[3],[4]-[7] modeB
< page_size=2k >
$5120-$5127 switch to mode A
$5128-$512b switch to mode B
$5121 [0]-[1] modeA
$5123 [2]-[3] modeA
$5125 [4]-[5] modeA
$5127 [6]-[7] modeA
$5129 [0]-[1],[4]-[5] modeB
$512b [2]-[3],[6]-[7] modeB
< page_size=1k >
$5120-$5127 switch to mode A
$5128-$512b switch to mode B
$5120 [0] modeA
$5121 [1] modeA
$5122 [2] modeA
$5123 [3] modeA
$5124 [4] modeA
$5125 [5] modeA
$5126 [6] modeA
$5127 [7] modeA
$5128 [0],[4] modeB
$5129 [1],[5] modeB
$512a [2],[6] modeB
$512b [3],[7] modeB
Consideration
MMC5 has mode A ,mode B and 2 kinds of CHR-page memory resistors.
They can be used for refreshing it. (?-SB)
5130 ???
analyzing it...
5200 W Split Mode Control 1
bit Ec-vvvvv
For the E function 0:don't use 1:use
c boundary's side is for using Split Mode extension of graphics
0: left side 1: right side
vvvvv left boundary is designated with the char. # to count places
Sample.
5200 <- #00
(not?) used yet
5200 <- #82
Used for SplitMode GFX extension from left 1-2 character
5200 <- #c2
Used for SplitMode GFX extension from the right side 3 chars.
5200 <- #c0
Used for SplitMode GFX extension on the whole screen
5200 <- #d0
Used for SplitMode GFX extension on the right side of the screen
5200 <- #90
Used for SplitMode GFX extension on the left side of the screen
5201 W SplitMode setup for SplitMode Ext. GFX use 1
$2005 determines the vertical movement; it can also delay ext. gfx's
vert. movement if necessary. It's written 2 times in bulk in the same
way as it would slip off a grade in $2005 (??-SB)
5202 W SplitMode setup for SplitMode Ext. GFX use 2
bit --pppppp
uses vertical division of ext. gfx CHR-page designation
index_size=4k(0x1000byte)
In case it uses a character 0x4000-0x4fff for the ext. gfx in question
$5202 <- 4
5203 W scanline break point
For scanline # that it splits and wants to make it designate it in bulk
5204 WR IRQ enable/disable
W bit I-------
I 1:IRQ Enable 0:IRQ Disable
R bit I-------
I 1:Scanline Hit 0:Scanline not Hit
$5203 is designated as scanline when arrived.
5205 WR mult input/output
5206 WR mult input/output
($5205in)*($5206in) = $5205,$5206out
5c00-5fbf ext. gfx business VRAM
shows an attribute of every position character
<ExGrafix Mode>
bit PPpppppp
PP: use character palette number
pppppp: use background CHR-PAGE number index=4k
#0-#3F are designations, $0000-$3FFF is CHR-data's range
Use for extension gfx
<Split Mode>
SplitMode uses a Name Table for extension gfx use.
bit pppppppp
pppppppp: use for background char. number designation
<ExRAM Mode>
Used for Extension RAM
5fc0-5fff
<ExGrafix Mode>
(not?) used yet
<Split Mode>
SplitMode uses gfx's Attribute Table extension.
PPU uses $23c0-$23ff in the same way as the Attribute Table
<ExRAM Mode>
Used for Extension RAM
Consideration
5c00-5fff has 3 uses.
Split Mode and ExGrafix Mode's VBlank is written so as to become
crowded, it writes a 0 and becomes crowded.
Every mode tries to go around ExRAM mode including reading but it
writes it, is effective in bulk and #5c-#5f is the output at times
where it is effective.