A/D Conversion; Figure 94. Adc Block Diagram - STMicroelectronics ST72361 Auto Series Manual

ST72361xx-Auto

Figure 94. ADC block diagram

AIN0
AIN1
AINx
17.3.2

A/D conversion

The analog input ports must be configured as input, no pull-up, no interrupt. Refer to the
Chapter 8: I/O
to be read as a logic input.
In the ADCCSR register:
●
Select the CS[3:0] bits to assign the analog channel to convert.
ADC conversion mode:
In the ADCCSR register:
●
Set the ADON bit to enable the A/D converter and to start the conversion. From this
time on, the ADC performs a continuous conversion of the selected channel.
When a conversion is complete:
● The EOC bit is set by hardware.
●
The result is in the ADCDR registers.
A read to the ADCDRH resets the EOC bit.
To read the 10 bits, perform the following steps:
1. Poll EOC bit
2. Read the ADCDRL register
3. Read the ADCDRH register. This clears EOC automatically.
To read only 8 bits, perform the following steps:
1. Poll EOC bit
2. Read the ADCDRH register. This clears EOC automatically.
f
CPU f f
CPU, CPU
EOC SPEED ADON SLOW
4
ANALOG
MUX
ADCDRH
ports. Using these pins as analog inputs does not affect the ability of the port
Doc ID 12468 Rev 3
f
ADC
/2 f /4
, CPU
CH3
CH2 CH1 CH0
D9 D8 D7 D6
ADCDRL
0
10-bit A/D converter (ADC)
ADCCSR
ANALOG TO DIGITAL
CONVERTER
D5 D4 D3 D2
0 0 0 0 0
D1 D0
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