Analog Inputs

The H8s have a twelve analog channels multiplexed to a single 10-bit Analog to Digital Converter.

Conversion Speed is 8.3 uS per channel.

REG Names

Digital output is loaded to following REGs:
(12 Channels x 2 for Hi and Lo Byte)
Address                REG Name
FEA0                     ADDR0H
FEA1                     ADDR0L
FEA2                     ADDR1H
FEA3                     ADDR1L
FEA4                     ADDR2H
FEA5                     ADDR2L
FEA6                     ADDR3H
FEA7                     ADDR3L
FEA8                     ADDR4H
FEA9                     ADDR4L
FEAA                    ADDR5H
FEAB                     ADDR5L
FEAC                     ADDR6H
FEAD                     ADDR6L
FEAE                     ADDR7H
FEAF                     ADDR7L
FEB0                     ADDR8H
FEB1                     ADDR8L
FEB2                     ADDR9H
FEB3                     ADDR9L
FEB4                     ADDRAH
FEB5                     ADDRAL
FEB6                     ADDRBH
FEB7                     ADDRBL

Sensor Assignment

The H8 DSMs, as well as most MAF based H8 cars, have the following assignments:

Channel -> Sensor
0 -> Coolant Temp
1 -> Air Temp
2 -> Barometric Pressure
3 -> Front O2 Voltage
4 -> Rear O2 Voltage
5 -> Battery Voltage
6 -> Knock Sensor Voltage
7 -> Throttle Position Sensor
8 -> Unknown/Unused
9 -> Unknown/Unused
A -> Unknown/Unused
B -> Manifold Differential Pressure Sensor


10-bit precision is general not kept, usually values are reduced to 8-bit (0-255) value.

Analog sensor values are refreshed once per main operating loop,
with the exception of the Knock Sensor which is updated on CAS interrupts also.