How to Use A/D Converter for S6J3110/ S6J3120 Series
Document No. 002-04457 Rev. *B
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3 . 1 . 9
F a i l u r e D i a g n o s i s F u n c t i o n
The 12-bit A/D converter has a failure diagnosis function. The AVRH and AVRL voltage conversion diagnosis.
This product has the function of fixing the input voltage level of the internal A/D converter to the AVRH or AVRL level
and perform A/D conversion.
3.2
A/D Activation Arbitration Functions
The A/D activation arbitration for each 12-bit A/D converter unit.
The A/D activation arbitration consists of the arbitration circuit, A/D activation trigger generation, and analog
channel number selection.
The A/D activation arbitration arbitrates an activation request from the A/D activation compare and generates
the activation trigger, A/D conversion cancellation signal, and analog channel number.
The A/D activation arbitration selects one from among the activation requests from different A/D activation
compares to generate the activation trigger. The A/D activation arbitration performs priority control when
activation requests from different A/D activation compares conflict with each other.
The priority orders are determined according to the following rules.
When an activation factor with the same priority order occurs while A/D conversion is stopped:
The activation factor with the smaller activation channel number is processed first.
When an activation factor with a different priority order occurs while A/D conversion is stopped:
The activation factor with the higher priority order is processed first.
When an activation factor with a higher priority order occurs while A/D conversion is in progress:
The current conversion is interrupted, and the activation factor with the higher priority order is processed.
Arbitration is performed again after this conversion, and then the processing of the interrupted activation factor
is restarted.
When an activation factor with a lower priority order occurs while A/D conversion is in progress:
Arbitration is again performed after the current conversion is completed, and then the activation factor with the
lower priority order is processed.
When an activation factor with the same priority order occurs while A/D conversion is in progress:
Arbitration is again performed after the current conversion is completed, and then the activation factor with the
same priority order is processed.
3.3
A/D Converter Control Functions
This section explains the functions of the 12-bit A/D converter control. A function for A/D-converting the analog
voltage that is input to the analog input pin (input voltage) into a digital value is supported and it has the following
features.
The conversion system used is an RC successive approximation conversion system with a sample hold circuit.
The analog input pin can be selected by the registers (make its setting in the A/D activation compare block).
1 sequence of A/D conversion is performed in response to 1 activation factor.
If another activation signal is input during A/D conversion, reactivation is performed. (Reactivation function)
If the A/D conversion cancellation signal is received during A/D conversion, the current processing is stopped and
initialized. (Forcible stop function)
For setting the sampling time, the sampling time setting that is common to all the channels or sampling time
setting for each channel can be selected.