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[[File:Cd2_ym2610.jpg|thumb|300px|right|YM2610 chip]]
{{ChipInfo
|picture=Cd2_ym2610.jpg
|pkg=SDIP64
|manu=yamaha
|date=1990 ?
|gates=
|used_on=All systems
}}


The YM2610 is a sound synthesis and playback chip made by Yamaha, which is used in all versions of the NeoGeo hardware.
The YM2610 is a sound synthesis and playback chip made by Yamaha, found in all versions of the NeoGeo hardware.
It was later merged with the [[Z80]] subsystem in the [[NEO-YSA]] and [[NEO-YSA2]] chips, which are used on some versions of the NeoGeo CD, [[CDZ]] and on [[ROM-Only boards]].
It was later merged with other chips in {{Chipname|NEO-YSA}} and {{Chipname|NEO-YSA2}}, which are used on some versions of the NeoGeo CD, the [[CDZ]], the {{PCB|MV1C}} and on [[ROM-Only boards]].


The chip relies on a [[YM3016]] external DAC (Digital to Analog Converter) chip for the FM and ADPCM sounds. The only direct analog output is for the SSG sounds. Both analog outputs are then mixed together before amplification.
The YM2610 requires a {{Chipname|YM3016}} external DAC (Digital to Analog Converter) chip for the [[FM]] and [[ADPCM]] sounds. The only direct analog output is for the [[SSG]] mono sounds. Both analog signals are then mixed together before amplification.


== Sound generation parts ==
The original YM2610 chip gets quite warm during normal operation.
Sound can come from 3 different generators, each having their own channel(s): SSG, FM synthesis and ADPCM playback.


=== SSG (Simple Sound Generator) ===
=Parts=
Given its limited capacities, the SSG is more often used for simple sound effects (coin sound, cursors in menus...) rather than music.
Sound comes from 3 different generators, each having their own channels:


The SSG has '''3 square wave channels''' with programmable frequency, and '''a LFSR noise channel''', all with programmable amplitude.
* [[SSG]] (Software Sound Generator): 3 channels
An unique enveloppe generator with predefined shapes can also be linked to the SSG's channels amplitudes.
* [[FM]] (Frequency Modulation): 4 channels
* [[ADPCM]] (Sample playback): 7 channels


See [[YM2610 registers#SSG|YM2610 registers: SSG]]
Providing 14 channels in total.


=== FM (Frequency Modulation) ===
=Programming=
The FM part has '''4 channels''', each having their own parametrable operators, panning and amplitude.
It's the most used way of producing music in games.


See [[YM2610 registers#FM|YM2610 registers: FM]]
See [[Z80/YM2610 interface]] and [[YM2610 registers]].


=== ADPCM (Adaptive Differential Pulse-Code Modulation) ===
=Pinout=
APDCM playback allows sampled sounds stored in the [[V ROM]]s or [[PCM file]]s to be played. It's used for anything that can't be easily synthesized like voices, percussions and wind instruments.


The ADPCM-A part has '''6 channels''', and a '''fixed''' playback frequency of: 8MHz (main clock) / 12 (prescaler) / 6 clocks per access / 6 channels = '''18.5185kHz'''.
[[File:Ym2610_pinout.png|right|640px]]


Audio is compressed as 4bit per sample and played back as 12bit.
* {{Sig|SDD|SDD*}}: {{Chipname|Z80}} data bus
* {{Sig|RAD|RAD*}}: ADPCM-A multiplexed address/data
* {{Sig|RMPX|RMPX}}: ADPCM-A address/data select
* {{Sig|ROE|ROE}}: APDCM-A data output enable
* {{Sig|RA|RA*}}: ADPCM-A address
* {{Sig|ANA|ANA}}: SSG analog output
* {{Sig|SH1|SH1}}: {{Chipname|YM3016}} latch 1
* {{Sig|SH2|SH2}}: YM3016 latch 2
* {{Sig|OP0|OP0}}: YM3016 serial data
* {{Sig|PA|PA*}}: ADPCM-B address
* {{Sig|POE|POE}}: ADPCM-B data output enable
* {{Sig|PMPX|PMPX}}: ADPCM-B address/data select
* {{Sig|PAD|PAD*}}: ADPCM-B multiplexed address/data
* {{Sig|IRQ|IRQ}}: Interrupt request output
* {{Sig|CS|CS}}: Chip select
* {{Sig|WR|WR}}: Write
* {{Sig|RD|RD}}: Read
* {{Sig|SDA|A*}}: Z80 address bus
* {{Sig|PHI M|PHI M}}: [[Clock]] input
* {{Sig|PHI S|PHI S}}: YM3016 clock output


The ADPCM-B part only has '''1 channel''', but the playback frequency can be changed from '''1.85kHz''' to: 18.5185 * 3 (1 access every 2 ADPCM-A channel access max) = '''55.555kHz'''.
<br clear="right"/>


Audio is compressed as 4bit per sample and played back as 16bit.
=Multiplexed ADPCM bus=


Samples can be any size from '''256 bytes to 1MiB, by 256 bytes steps'''. '''Samples cannot cross 1MB pages''' (the 4 MSBs of the end address should be equal to the start address).
Access to the [[V ROM]]s are made via partly multiplexed buses. See [[YM2610 bus timing]] for more details about the access sequences.


See [[YM2610 registers#ADPCM-A|YM2610 registers: ADPCM-A]] and [[YM2610 registers#ADPCM-B|ADPCM-B]]
The {{Sig|SDRMPX|SDRMPX}} and {{Sig|SDPMPX|SDPMPX}} signals are used to control latches or the {{Chipname|PCM}} chip in [[cartridges]] to demultiplex address and data. When {{Sig|SDROE|SDROE}} or {{Sig|SDPOE|SDPOE}} goes low, SDRAD* and SDPAD* are tristated so that the V ROMs can output data.


==CPU communication==
* SDRA* for ADPCM-A
 
See [[Z80/YM2610 interface]].
 
==Multiplexed PCM bus==
 
[[File:Ym2610_pinout.png|right|256px]]
 
Access to the V ROMs are made via partly multiplexed buses. See [[YM2610 bus timing]] for more details about the access sequences.
 
The {{Sig|SDRMPX|SDRMPX}} and {{Sig|SDPMPX|SDPMPX}} signals are used to drive latches or the [[PCM]] chip in [[cartridge boards|cartridges]] to demultiplex data. When {{Sig|SDROE|SDROE}} or {{Sig|SDPOE|SDPOE}} goes low, SDRAD* and SDPAD* are tristated so that the V ROMs can output data.
 
*SDRA* for ADPCM-A


{|class="wikitable"
{|class="wikitable"
!SDRMPX
!rowspan="2"|SDRMPX edge
!colspan="8"|SDRAD*
!colspan="8"|SDRAD*
!colspan="6"|SDRA*
!colspan="6"|SDRA*
|-
|-
|
!0
!0
!1
!1
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|}
|}


*SDPA* for ADPCM-B
* SDPA* for ADPCM-B


{|class="wikitable"
{|class="wikitable"
!SDPMPX
!rowspan="2"|SDPMPX edge
!colspan="8"|SDPAD*
!colspan="8"|SDPAD*
!colspan="6"|SDPA*
!colspan="6"|SDPA*
|-
|-
|
!0
!0
!1
!1
Line 156: Line 165:
|}
|}


24 bits allows for 16MiB max V ROMs (without bankswitching).
24 address bits allow for 16MiB max V ROMs (without bankswitching).
 
=Trivia=


== Trivia ==
* A lot of games have several recordings of the same instrument playing different notes, rather than having only one sample and change the ADPCM-B playback frequency to vary its pitch. (Trumpet in [[Viewpoint]], electric guitar in [[Super Sidekicks]]). Why ?
* Nazca's [[sound driver]]s are able to use the SSG channels for music playback. (Maybe all can ?)


*A lot of games have several recordings of the same instrument playing different notes, rather than having only one sample and change the ADPCM-B playback frequency to vary its pitch. (Trumpet in [[Viewpoint]], electric guitar in [[Super Sidekicks]]). Why ?
=Datasheet=
*Nazca's [[sound driver]]s are able to use the SSG channels for music playback. (Maybe all can ?)


== Datasheet ==
Japanese datasheet: [[http://www.ajworld.net/neogeodev/ym2610am_en.html ajworld.net]]


Incomplete/translated datasheet: [[http://furrtek.free.fr/noclass/neogeo/YM2610.pdf YM2610.pdf]]
Incomplete/translated datasheet: [[http://furrtek.free.fr/noclass/neogeo/YM2610.pdf YM2610.pdf]]

Latest revision as of 18:19, 26 July 2017

Package SDIP64
Manufacturer
First use 1990 ?
Used on All systems

The YM2610 is a sound synthesis and playback chip made by Yamaha, found in all versions of the NeoGeo hardware. It was later merged with other chips in NEO-YSA and NEO-YSA2, which are used on some versions of the NeoGeo CD, the CDZ, the MV1C and on ROM-Only boards.

The YM2610 requires a YM3016 external DAC (Digital to Analog Converter) chip for the FM and ADPCM sounds. The only direct analog output is for the SSG mono sounds. Both analog signals are then mixed together before amplification.

The original YM2610 chip gets quite warm during normal operation.

Parts

Sound comes from 3 different generators, each having their own channels:

  • SSG (Software Sound Generator): 3 channels
  • FM (Frequency Modulation): 4 channels
  • ADPCM (Sample playback): 7 channels

Providing 14 channels in total.

Programming

See Z80/YM2610 interface and YM2610 registers.

Pinout

  • SDD: Z80 data bus
  • RAD: ADPCM-A multiplexed address/data
  • RMPX: ADPCM-A address/data select
  • ROE: APDCM-A data output enable
  • RA: ADPCM-A address
  • ANA: SSG analog output
  • SH1: YM3016 latch 1
  • SH2: YM3016 latch 2
  • OP0: YM3016 serial data
  • PA: ADPCM-B address
  • POE: ADPCM-B data output enable
  • PMPX: ADPCM-B address/data select
  • PAD: ADPCM-B multiplexed address/data
  • IRQ: Interrupt request output
  • CS: Chip select
  • WR: Write
  • RD: Read
  • SDA: Z80 address bus
  • PHI M: Clock input
  • PHI S: YM3016 clock output


Multiplexed ADPCM bus

Access to the V ROMs are made via partly multiplexed buses. See YM2610 bus timing for more details about the access sequences.

The SDRMPX and SDPMPX signals are used to control latches or the PCM chip in cartridges to demultiplex address and data. When SDROE or SDPOE goes low, SDRAD* and SDPAD* are tristated so that the V ROMs can output data.

  • SDRA* for ADPCM-A
SDRMPX edge SDRAD* SDRA*
0 1 2 3 4 5 6 7 8 9 20 21 22 23
Low to high 0 1 2 3 4 5 6 7 8 9 ? ? ? ?
High to low 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  • SDPA* for ADPCM-B
SDPMPX edge SDPAD* SDPA*
0 1 2 3 4 5 6 7 8 9 10 11
Low to high 0 1 2 3 4 5 6 7 8 9 10 11
High to low 12 13 14 15 16 17 18 19 20 21 22 23

24 address bits allow for 16MiB max V ROMs (without bankswitching).

Trivia

  • A lot of games have several recordings of the same instrument playing different notes, rather than having only one sample and change the ADPCM-B playback frequency to vary its pitch. (Trumpet in Viewpoint, electric guitar in Super Sidekicks). Why ?
  • Nazca's sound drivers are able to use the SSG channels for music playback. (Maybe all can ?)

Datasheet

Japanese datasheet: [ajworld.net]

Incomplete/translated datasheet: [YM2610.pdf]