TZR250 3MA
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This info page is for the Icp12 development.
If we understand the Normal behavior off the 3MA CDI, we can use the signals better for the Icp12 project.

Fond the IC type used in the 3MA CDI's, Its the FUJITSU MB88501H
All what I can measure, falls into its place when comparing it with its datasheed.

Will try to explain my findings step by step (pin by pin)

Pin 1 (R4) is not connected to anything (complete loose)
Pin 2 (R5) is not connected to anything (complete loose)
Pin 3 (R6) is not connected to anything (complete loose)
Pin 4 (R7) is not connected to anything (complete loose)
Pin 5 (R8) is a pulse (5V) witch is sent to the TA8050P (servo driver) is pulse length is the time the motor is active.
Pin 6 (R9) is a pulse (5V) witch is sent to the TA8050P (servo driver) is pulse length is the time the motor is active.
Pin 7 (R10) is not connected to anything (complete loose)
Pin 8 (R11) is not connected to anything (complete loose)
Pin 9 (R12) is not connected to anything (complete loose)
Pin 10 (R13) Main Ground (0V)
Pin 11 (R14) is not connected to anything (complete loose)
Pin 12 (K0) is not connected to anything (complete loose)
Pin 13 (K1) Digital pickup pulse
Pin 14 (K2) is not connected to anything (complete loose)
Pin 15 (K3) is not connected to anything (complete loose)
Pin 16 (EX) External clock
Pin 17 (X)  External clock
Pin 18 (Reset) Reset pulse given from a TA8000S
Pin 19 (IRQ) is not connected to anything (complete loose)
Pin 20 (TC) is not connected to anything (complete loose)
Pin 21 (Vss) Main ground (0V)

Pin 22 (SC/TO) Digital ignition pulse out.
Pin 23 (SI) Digital ignition in (back off lobe ignition pulse)
Pin 24 (SO) Digital ignition in (back off lobe ignition pulse)
Pin 25 (O0) Timer pulse for the TA8000S (60Hz)
Pin 26 (O1) solenoid 2
Pin 27 (O2) solenoid 1
Pin 28 (O3) is not connected to anything (complete loose)
Pin 29 (O4) is not connected to anything (complete loose)
Pin 30 (O5) Ground (0V)
Pin 31 (O6) Ground (0V)
Pin 32 (O7) 5V Main
Pin 33 (P0) Speed limiter signal
Pin 34 (P1) Ground (0V)
Pin 35 (P2) TPS sensor
Pin 36 (P3) YPVS sensor
Pin 37 (R0) is not connected to anything (complete loose)
Pin 38 (R1) is not connected to anything (complete loose)
Pin 39 (R2) is not connected to anything (complete loose)
Pin 40 (R3) is not connected to anything (complete loose)
Pin 41 (Start) is not connected to anything (complete loose)
Pin 42 (Vcc) 5V Main
Pin 5 and 5 YPVS control

From pin 5 and 6 comes a digital 5V output pulse witch varies in length
You have on Pin 5 the closing pulse and on Pin 6 the Opening pulse
The length off the pulses depends on the voltage given by the ypvs sensor the IC know witch voltage needs to be set at a certain rpm so it gives a pulse until it reach that voltage

Step/pulses measured: (with a slight variation depending if it is closing or opening)
Close is 0,81V
Step 1  0,86V
Step 2  0,98V
Step 3  1,14V
Step 4  1,23V
Step 5  1,33V
Step 6  1,49V
Step 7  1,68V
Step 8  1,79V
Step 9  1,87V
Step 10 2,02V
Step 11 2,16V
Step 12 2,25V

The speed limiter pulse is a programmed voltage to, its allways 1,91V close and 2,25V fully open.
Pin 13 Digital incoming pickup pulse.

This is a generated digital 5V pulse coming from the T2333
It is created from the pickup (mounted at the flywheel) witch goes trough a couple of resistors (and other components) until it is good enough for the T2333 to work with. This device makes it a usable incoming signal for the IC (pin13) to use
Pin 16 and 17 clock

These pins are used for the external clock witch is mounted on the 3MA CDI
It has to do with the speed and synchronization off the calculation inside the IC (this is a set speed and can't be changed)
Pin 18 Reset

On Pin 18 comes the RESET pulse this is a pulse coming from the TA8000S a chip mounted on the 3MA CDI
Its purpose is to start at its begin point of the IC firmware (example after power set to 0V, engine stop, etc)
It is the starting point of the software written inside the IC
Pin 21 Vss

This is the main Ground (0V) from the IC, also different pin number from the IC uses the same ground
Pin 22 outgoing ignition pulse

This is the outgoing digital ignition pulse going to the thyristor witch controls the discharging of the capacitor (spark)

Its a bid tricky as this outgoing signal goes over the T2333 witch has multiple functions on the 3MA CDI circuit board.
The T2333 controls the ignition firing at the back off the lobe until 60Hz, after 60Hz the IC is taken over with its programmed ignition curve.
Pin 23 and 24 incoming ignition pulse

These are a bid a ministry, long I have thought its a outgoing ignition pulse (back point off the lobe)
But now I have a feeling its a incoming signal coming from the T2333 and the IC use it to fire at the back off the lobe. (or for internal calculations)

Pin 25 timer pulse

This is a outgoing signal 60Hz with is used for the TA8000S
The TA8000S is used for the Reset signal it needs a timer/clock pulse to synchronize it self
Pin 26 and 27

These are outgoing signals to control the airjets on the 3MA (air solenoids)
They are active depending on incoming rpm and uses a internal programmed field when to be active or not
Pin 33 Speed signal

This is a incoming signal from the speed limiter (inside the speedometer) its a 2,48V or a 4,84V
2,48V is metal tap not between optic's
4,84V Metal tap between optic's

Pin 35 TPS signal

The TPS signal is a incoming signal. (its coming from the sensor on the 3MA cabs)
It is there to use the different ignition curves stored inside the IC
Different voltage means different ignition curves.

Well known voltages coming on pin 35
1.25V to 2.00V Curve 1/2 till 1
2.00V to 2.75V Curve 1/4 till 1/2
2.75V to 3.75V Curve 1/8 till 1/4
3.75V to 4.50V Curve    0 till 1/8

Pin 36 YPVS sensor

This is a incoming signal form the Sensor inside the YPVS unit. (It is there to know the position off the exhaust valve)
The received voltage on pin 36 is used for calculation off the YPVS pulses given on Pin 5 and 6
A certain voltage means a certain exhaust position desired at a certain rpm
All digital pulses are 0 to 5V or 5V to 0V (block signal)
All variable signals are voltages between 5V and 0V or 0 to 5V
Ground is a solid 0V
Main IC voltage is 5V
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