CHAPTER 12 A/D CONVERTER
Preliminary User’s Manual U16315EJ1V0UD
241
(3) Conflicting operations
<1>
Conflict between A/D conversion result register (ADCR) write and ADCR read by instruction upon the end
of conversion
ADCR read has priority. After the read operation, the new conversion result is written to ADCR.
Old data can be read from ADCR at the timing of (1) and new data can be read from ADCR at the timing of
(2) as shown in Figure 12-20. A master-slave configuration is employed for transferring the A/D conversion
result to ADCR.
Figure 12-20. Storing Conversion Result in ADCR and Timing of Data Read from ADCR
(1) Timing to read old data
Internal clock
INTAD
Master write signal
A/D conversion (master)
Slave write signal
ADCR (slave)
Read data
Conversion
end
Conversion
result N
Conversion result N
Conversion result N
Conversion result N + 1
(2) Timing to read new data
Internal clock
INTAD
Master write signal
A/D conversion (master)
Slave write signal
ADCR (slave)
Read data
Conversion
end
Conversion
result N
Conversion result N + 1
Conversion result N + 1
Conversion result N + 1
<2>
Conflict between ADCR write and A/D converter mode register (ADM) write or analog input channel
specification register (ADS) write upon the end of conversion
ADM or ADS write has priority. ADCR write is not performed, nor is the conversion end interrupt signal
(INTAD) generated.