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ay8910.cpp: add pinout, remove outdated comments from .h [Lord Nightmare]

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Lord-Nightmare 2017-05-30 20:09:30 -04:00
parent b88e325140
commit 2573117b74
2 changed files with 92 additions and 15 deletions
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92
src/devices/sound/ay8910.cpp
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@ -251,6 +251,98 @@ has twice the steps, happening twice as fast.
***************************************************************************/
/**
AY-3-8910/8914/YM2149 (YM3439? others?)
_______ _______
_|* \__/ |_
[4] VSS (GND) -- |_|1 40|_| -- VCC (+5v)
_| |_
[5] NC |_|2 39|_| <- TEST 1 [1]
_| |_
ANALOG CHANNEL B <- |_|3 38|_| -> ANALOG CHANNEL C
_| |_
ANALOG CHANNEL A <- |_|4 37|_| <> DA0
_| |_
[5] NC |_|5 36|_| <> DA1
_| |_
IOB7 <> |_|6 35|_| <> DA2
_| |_
IOB6 <> |_|7 34|_| <> DA3
_| /---\ |_
IOB5 <> |_|8 \-/ | A 33|_| <> DA4
_| . . Y |_
IOB4 <> |_|9 |---| - S 32|_| <> DA5
_| ' ' 3 O |_
IOB3 <> |_|10 8 - U 31|_| <> DA6
_| 3 8 N |_
IOB2 <> |_|11 0 9 D 30|_| <> DA7
_| 8 1 |_
IOB1 <> |_|12 0 29|_| <- BC1
_| P |_
IOB0 <> |_|13 28|_| <- BC2
_| |_
IOA7 <> |_|14 27|_| <- BDIR
_| |_
IOA6 <> |_|15 26|_| <- TEST 2 [2]
_| |_
IOA5 <> |_|16 25|_| <- A8 [3]
_| |_
IOA4 <> |_|17 24|_| <- /A9 [3]
_| |_
IOA3 <> |_|18 23|_| <- /RESET
_| |_
IOA2 <> |_|19 22|_| == CLOCK
_| |_
IOA1 <> |_|20 21|_| <> IOA0
|__________________|
[1] Based on the decap, TEST 1 affects the Envelope Generator and/or the
frequency divider somehow.
[2] The TEST 2 input connects to the same selector as A8 and /A9 do on the 8910
and appears to act as just another active high enable like A8(pin 25) and
has an internal pull-up so if left NC the chip remains enabled.
On the 8914, it performs the same above function but additionally ?disables?
the DA0-7 bus if pulled low/active. This additional function was removed
on the 8910.
on YM2149 and YM3439 this pin is /SEL, if low, clock input is /2
[3] It is possible for A8 and /A9 pins to be mask programmed to have different
active polarities. This might be true on the AY-3-8916/17 parts used on the
Intellivision ECS module? (not the Keyboard module?)
[4] The bond wire for the VSS pin goes to the substrate frame, and then a
separate bond wire connects it to a pad between pins 21 and 22
[5] These pins lack internal bond wires entirely.
AY-3-8910/A: 2 I/O ports
AY-3-8912/A: 1 I/O port; /A9 doesn't exist and is considered pulled low.
AY-3-8913/A: 0 I/O port; BC2 pin doesn't exist and is considered pulled high.
Factory default for these three types when writing address data to them is:
/A9 must be low, A8 must be high, A7 thru A4 must be low.
A7 thru A4 enable state can be changed with a factory mask adjustment but
default was 0000 for the "common" part shipped.
The 'A' version of the 3 above have a re-laid out die, unclear if there are
any behavior changes vs the non-'A' version.
AY-3-8914: same as 8910 except for different register mapping and two bit
envelope enable / volume field.
Factory default for these three types when writing address data to them is:
/A9 must be low, A8 must be high, A7 thru A4 must be low.
A7 thru A4 enable state can be changed with a factory mask adjustment but
are unknown for the one known part shipped, used in the Intellivision.
AY8930: mostly backwards compatible with 8910, except like the AY-3-8913, the
BC2 pin is considered tied high/permanently '1'.
If the AY8930's extended mode is enabled, it gains higher resolution
frequency and volume control, separate volume per-channel, and the duty
cycle can be adjusted for the 3 channels. If the mode is not enabled, it
behaves exactly(?) like an AY-3-8910.
YM2149: The envelope register has 5 bits of resolution internally, allowing for
smoother volume ramping, though the register for setting its direct value
remains 4 bits wide. The chip also has a selectable clock divider on pin 26
(/SEL), which was /TEST2 on the AY-3-8910. If low, the input clock is halved.
YM3439: limited info: CMOS version of YM2149?
YMZ284: limited info: 0 I/O port, different clock divider
YMZ294: limited info: 0 I/O port
OKI M5255, Winbond WF19054, JFC 95101, File KC89C72, Toshiba T7766A : differences to be listed
*/
#include "emu.h"
#include "ay8910.h"

15
src/devices/sound/ay8910.h
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@ -5,21 +5,6 @@
#pragma once
/*
AY-3-8910A: 2 I/O ports
AY-3-8912A: 1 I/O port
AY-3-8913A: 0 I/O port
AY-3-8914: same as 8910 except for different register mapping and two bit envelope enable / volume field
AY8930: upper compatible with 8910.
In extended mode, it has higher resolution and duty ratio setting
YM2149: higher resolution, selectable clock divider
YM3439: same as 2149
YMZ284: 0 I/O port, different clock divider
YMZ294: 0 I/O port
OKI M5255, Winbond WF19054, JFC 95101, File KC89C72, Toshiba T7766A : differences to be listed
*/
#define ALL_8910_CHANNELS -1
/* Internal resistance at Volume level 7. */