TriOS/lib/adm-ay.spin

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2013-12-10 15:32:47 +01:00
{{
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ AYcog - AY-3-891X / YM2149 emulator V0.22 (C) 2010-05 Johannes Ahlebrand │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ TERMS OF USE: Parallax Object Exchange License │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation │
│files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, │
│modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software│
│is furnished to do so, subject to the following conditions: │
│ │
│The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.│
│ │
│THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE │
│WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR │
│COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
│ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
}}
CON
PSG_FREQ = 2_000_000.0 ' Clock frequency input to the chip (Colour Genie EG2000 computer runs at 2.2Mhz)
' WARNING !!
' Don't alter the constants below unless you know what you are doing
'-------------------------------------------------------------------
SAMPLE_RATE = 125_000 ' Sample rate of AYcog
OSC_CORR = trunc(1.05 * PSG_FREQ) ' Calibrates the relative oscillator frequency
NOISE_CORR = OSC_CORR>>1 ' Calibrates the relative noise frequency
ENV_CORR = OSC_CORR>>6 ' Calibrates the relative envelope timing
'
' Reg bits function
' -----------------------------------
' 00 7..0 channel A fine tune
' 01 3..0 channel A coarse tune
' 02 7..0 channel B fine tune
' 03 3..0 channel B coarse tune
' 04 7..0 channel C fine tune
' 05 3..0 channel C coarse tune
' 06 4..0 noise period
' 07 7..0 enable register
' 08 4..0 channel A volume
' 09 4..0 channel B volume
' 10 4..0 channel C volume
' 11 7..0 envelope fine tune
' 12 7..0 envelope coarse tune
' 13 3..0 envelope shape
' 14 7..0 I/O port A value
' 15 7..0 I/O port B value
VAR
long cog
PUB start(right,left,AYregisters)
if (AYregisters & 1) <> 0 ' we need word aligned registers
abort(-1)
arg1 := $18000000 | left
arg2 := $18000000 | right
r1 := ((1<<right) | (1<<left))&!1
sampleRate := clkfreq/SAMPLE_RATE
cog := cognew(@AYEMU,AYregisters) + 1
return cog
PUB stop
if cog
cogstop(cog~ -1)
dat org 0
'
' Assembly AY emulator
'
AYEMU mov AY_Address, par ' Setup everyting
mov dira, r1
mov ctra, arg1
mov ctrb, arg2
mov waitCounter, cnt
add waitCounter, sampleRate
'-----------------------------------------------------------
mainLoop call #getRegisters
call #AY ' Main loop
call #mixer
jmp #mainLoop
'
' Read all AY registers from hub memory and convert
' them to more convenient representations.
'
getRegisters mov tempValue, AY_Address
rdword frequency1, tempValue ' reg 0+1 Read in all 4
shl frequency1, #20 ' frequency registers
add tempValue, #2 ' and make them "32 bits"
rdword frequency2, tempValue ' reg 2+3
shl frequency2, #20
add tempValue, #2
rdword frequency3, tempValue ' reg 4+5
shl frequency3, #20
add tempValue, #2
rdbyte noisePeriod, tempValue ' reg 6
and noisePeriod, #$1f
add tempValue, #1
rdbyte enableRegister, tempValue ' reg 7
min noisePeriod, #1
add tempValue, #1
rdbyte amplitude1, tempValue ' reg 8
and amplitude1, #31
add tempValue, #1
rdbyte amplitude2, tempValue ' reg 9
and amplitude2, #31
add tempValue, #1
rdbyte amplitude3, tempValue ' reg 10
and amplitude3, #31
add tempValue, #1
rdbyte envelopePeriod, tempValue ' reg 11
add tempValue, #1
shl noisePeriod, #20
rdbyte temp1, tempValue ' reg 12
shl temp1, #8
or envelopePeriod, temp1 wz
if_z mov envelopePeriod, half_period ' 0 == half the period of 1
if_nz shl envelopePeriod, #16
add tempValue, #1
rdbyte envelopeShape, tempValue ' reg 13
movd oscValues, enableRegister
getRegisters_ret ret
'
' Calculate AY samples channel 1-3 and store in out1-out3
'
AY
'───────────────────────────────────────────────────────────
'───────────────────────────────────────────────────────────
' Envelope shaping -> envelopeAmplitude
'───────────────────────────────────────────────────────────
Envelope sub envCounter, envSubValue wc ' Handles envelope incrementing
if_c add envCounter, envelopePeriod
if_c add envelopeValue, envelopeInc
'───────────────────────────────────────────────────────────
test envelopeShape, #16 wz ' Handle envelope reset bit ( Extra bit added by Ahle2 )
if_z neg envelopeValue, #0
if_z mov envelopeInc, #1
if_z mov envCounter, envelopePeriod
if_z or envelopeShape, #16
if_z wrbyte envelopeShape, tempValue '<-IMPORTANT, sets bit 5 in hub ram
'───────────────────────────────────────────────────────────
test envelopeShape, #8 wc ' Handle continue = 0
test envelopeShape, #4 wz
if_nc_and_z mov envelopeShape, #9
if_nc_and_nz mov envelopeShape, #15
'───────────────────────────────────────────────────────────
test envelopeShape, #2 wz ' Sets the envelope hold level
muxz envHoldLevel, #15 '
'───────────────────────────────────────────────────────────
test envelopeValue, #16 wz ' Check if > 15
test envelopeShape, #1 wc ' Check hold bit
if_nz_and_c mov envelopeInc, #0 ' Hold envelope
if_nz_and_c mov envelopeValue, envHoldLevel '
'───────────────────────────────────────────────────────────
if_nz test envelopeShape, #2 wc ' Check and handle alternation
if_nz_and_c neg envelopeInc, envelopeInc
if_nz_and_c add envelopeValue, envelopeInc
'───────────────────────────────────────────────────────────
mov envelopeAmplitude, envelopeValue
test envelopeShape, #4 wc ' Check and handle invertion (attack)
if_nc xor envelopeAmplitude, #15 '(Move Value or ~Value to envelopeAmplitude)
'───────────────────────────────────────────────────────────
' Waveform shaping noise -> bit 3 of oscValues
'───────────────────────────────────────────────────────────
Noise1 sub phaseAccumulatorN, noiseSubValue wc ' Noise generator
if_c add phaseAccumulatorN, noisePeriod
if_c add noiseValue, noiseAdd
if_c ror noiseValue, #15 wc
if_c xor oscValues, #8
'───────────────────────────────────────────────────────────
' Waveform shaping channel 1 -> out1
'───────────────────────────────────────────────────────────
Env1 test amplitude1, #16 wz ' Selects envelope or fixed amplitude
if_nz mov amplitude1, envelopeAmplitude ' depending on bit 5 of amplitude register 1
mov arg1, amplitude1
call #getAmplitude
'───────────────────────────────────────────────────────────
Square1 cmp frequency1, freqRef wc
if_nc sub phaseAccumulator1, oscSubValue wc ' Square wave generator
if_c add phaseAccumulator1, frequency1 ' channel 1
if_c xor oscValues, #1
'───────────────────────────────────────────────────────────
test oscValues, mask513 wz ' Handles mixing of channel 1
negnz out1, r1 ' Tone on/off, Noice on/off
test oscValues, mask4104 wz
if_z mov out1, r1 ' arg2 = (ToneOn | ToneDisable) & (NoiseOn | NoiseDisable)
'───────────────────────────────────────────────────────────
' Waveform shaping channel 2 -> out2
'───────────────────────────────────────────────────────────
Env2 test amplitude2, #16 wz ' Selects envelope or fixed amplitude
if_nz mov amplitude2, envelopeAmplitude ' depending on bit 5 of amplitude register 2
mov arg1, amplitude2
call #getAmplitude
'───────────────────────────────────────────────────────────
Square2 cmp frequency2, freqRef wc
if_nc sub phaseAccumulator2, oscSubValue wc ' Square wave generator
if_c add phaseAccumulator2, frequency2 ' channel 2
if_c xor oscValues, #2
'───────────────────────────────────────────────────────────
test oscValues, mask1026 wz ' Handles mixing of channel 2
negz out2, r1 ' Tone on/off, Noice on/off
test oscValues, mask8200 wz
if_z mov out2, r1 ' arg2 = (ToneOn | ToneDisable) & (NoiseOn | NoiseDisable)
'───────────────────────────────────────────────────────────
' Waveform shaping channel 3 -> out3
'───────────────────────────────────────────────────────────
Env3 test amplitude3, #16 wz ' Selects envelope or fixed amplitude
if_nz mov amplitude3, envelopeAmplitude ' depending on bit 5 of amplitude register 3
mov arg1, amplitude3
call #getAmplitude
'───────────────────────────────────────────────────────────
Square3 cmp frequency3, freqRef wc
if_nc sub phaseAccumulator3, oscSubValue wc ' Square wave generator
if_c add phaseAccumulator3, frequency3 ' channel 3
if_c xor oscValues, #4
'───────────────────────────────────────────────────────────
test oscValues, mask2052 wz ' Handles mixing of channel 2
negz out3, r1 ' Tone on/off, Noice on/off
test oscValues, mask16392 wz
if_z mov out3, r1 ' arg2 = (ToneOn | ToneDisable) & (NoiseOn | NoiseDisable)
AY_ret ret
'
' Mix channels and update FRQA/FRQB PWM-values
'
mixer mov r1, val31bit ' DC offset
add r1, out1
add r1, out2
add r1, out3
waitcnt waitCounter, sampleRate ' Wait until the right time to update
mov FRQA, r1 '| Update PWM values in FRQA/FRQB
mov FRQB, r1 '|
mixer_ret ret
'
' Get amplitude table r1 = amplitudTable[arg1]
'
getAmplitude and arg1, #15
add arg1, #amplitudeTable ' Lookup the amplitude according
movs :indexed1, arg1 ' to the current state of the envelope
nop
:indexed1 mov r1, 0
getAmplitude_ret ret
'
' Variables, tables, masks and reference values
'
amplitudeTable long 1634706
long 2452059
long 3678089
long 5517133
long 8275700
long 12413550
long 18620325
long 27930488
long 41895733
long 62843600
long 94265400
long 141398100
long 212097150
long 318145725
long 477218588
long 715827882
'Masks and reference values
mask513 long 513
mask1026 long 1026
mask2052 long 2052
mask4104 long 4104
mask8200 long 8200
mask16392 long 16392
mask32bit long $ffffffff
mask16bit long $ffff
half_period long $00008000
val31bit long $80000000
noiseAdd long $88008800 'Value to add to the noise generator every noise update
sampleRate long 0
freqRef long 10<<20
'Setup and subroutine parameters
arg1 long 0
arg2 long 0
r1 long 0
AY_Address long 0
'AY variables
envCounter long 1
envSubValue long ENV_CORR
oscSubValue long OSC_CORR
noiseSubValue long NOISE_CORR
envelopeValue long 0
envelopeInc long 1
envHoldLevel res 1
oscValues res 1
amplitude1 res 1
amplitude2 res 1
amplitude3 res 1
envelopeAmplitude res 1
enableRegister res 1
envelopeShape res 1
frequency1 res 1
frequency2 res 1
frequency3 res 1
envelopePeriod res 1
noisePeriod res 1
phaseAccumulatorN res 1
phaseAccumulator1 res 1
phaseAccumulator2 res 1
phaseAccumulator3 res 1
noiseValue res 1
noiseOut res 1
out1 res 1
out2 res 1
out3 res 1
waitCounter res 1
tempValue res 1
temp1 res 1
fit