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[[Catégorie:Chips]]
{{ChipInfo
[[Catégorie:Audio system]]
|picture=Cd2_ym2610.jpg
|pkg=SDIP64
|manu=yamaha
|date=1990 ?
|gates=
|used_on=All systems
}}


[[File:Cd2_ym2610.jpg|thumb|300px|right|YM2610 chip]]
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 {{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 YM2610 is a sound synthesis chip made by Yamaha, used in every of the NeoGeo's hardware versions.
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.
It was merged with the [[Z80]], the [[YM3016]] and the Z80 memory controler in the [[NEO-YSA]] chip on late revisions of the NeoGeo CD and CDZ.


Its analog outputs only sound generated by the SSG. The FM and ADPCM parts use an external [[YM3016]] DAC.
The original YM2610 chip gets quite warm during normal operation.


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


The YM2610 is programmed through 4 ports. They're usually called Address A, Data A, Address B, Data B.
* [[SSG]] (Software Sound Generator): 3 channels
They're respectively linked to the Z80's ports 4 to 7.
* [[FM]] (Frequency Modulation): 4 channels
* [[ADPCM]] (Sample playback): 7 channels


== Sound generation parts ==
Providing 14 channels in total.
Its able to produce sound using SSG, FM synthesis and ADPCM playback.


=== SSG (Simple Sound Generator) ===
=Programming=
Given its limited capacities, the SSG is rarely used for music in NeoGeo games. It's more often used for sound effects like coin-in, continue countdowns or "GO >>>" indicators in side-scrollers.


The SSG part has 3 square wave channels with programmable frequency, and a LFSR noise channel, all with programmable amplitude.
See [[Z80/YM2610 interface]] and [[YM2610 registers]].
An unique enveloppe generator with predefined shapes can also be linked to the SSG's channels amplitudes.
(Is SSG only mono ?)


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


=== ADPCM ===
[[File:Ym2610_pinout.png|right|640px]]
APDCM playback allows sampled sounds to be played along with the synthesized ones. Its used for anything that can't be easily synthesized like voices, percussions or wind instruments. Viewpoint uses a lot of sampled drum loops and explosion sounds.


The ADPCM-A part has 6 channels, with a fixed playback frequency of 18.5kHz. Samples can be any size from 256 bytes to 1MB, by 256 bytes increments.
* {{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 frequency can be changed.
<br clear="right"/>
 
=Multiplexed ADPCM bus=
 
Access to the [[V ROM]]s 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 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.
 
* SDRA* for ADPCM-A
 
{|class="wikitable"
!rowspan="2"|SDRMPX edge
!colspan="8"|SDRAD*
!colspan="6"|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
 
{|class="wikitable"
!rowspan="2"|SDPMPX edge
!colspan="8"|SDPAD*
!colspan="6"|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 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]]
 
[[Category:Chips]]
[[Category:Audio system]]

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]

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