Counting Of Discharge Time With Counter; Operational Waveform - Hitachi 902 Service Manual

Conventional
Double integral type A/D ×
Type
Main
wavelength
Sub
wavelength

Operational waveform

Charge Discharge
3.6 ms
EMIO 100
Main wavelength
Sub wavelength
ISE
Temperature
Operational waveform
ADC operation
The ADC whose conversion rate is 25 µsec is operated at intervals of 400 µsec 32 times and
from the data thus obtained, the maximum and minimum values are deleted.
After that, the average value is calculated and output to the main CPU as a 16-bit A/D value.
In case of simultaneous measurement at two wavelengths, the above operation is conducted
while changing the MPX at intervals of 200 µsec and two 16-bit A/D values separately
calculated in H8 for the main and sub wavelengths are output.
Exclusive
Analog
controller
part

Counting of discharge time with counter

MPX
Sequential
compariso
n type ADC
25 µs
400 µs
Approx. 13 msec (32 times)
6809
Reset
10 ms
Exclusive
controller
(H8/330)
10 - 12
ROM RAM
Peripheral
circuit
DPRAM
DPRAM
Main
CPU
Main
CPU