ST72321R6-Auto STMicroelectronics, ST72321R6-Auto Datasheet - Page 173

• Manufacturer Part Number: ST72321R6-Auto
• Description: 8-bit MCU for automotive with 32 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321R6-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

ST72321xx-Auto
17.3
17.3.1
17.3.2
Note:
Functional description
The conversion is monotonic, meaning that the result never decreases if the analog input
does not and never increases if the analog input does not.
If the input voltage (V
conversion result is FFh in the ADCDRH register and 03h in the ADCDRL register (without
overflow indication).
If the input voltage (V
conversion result in the ADCDRH and ADCDRL registers is 00 00h.
The A/D converter is linear and the digital result of the conversion is stored in the ADCDRH
and ADCDRL registers. The accuracy of the conversion is described in
Electrical
R
is too high, this will result in a loss of accuracy due to leakage and sampling not being
completed in the allotted time.
A/D converter configuration
The analog input ports must be configured as input, no pull-up, no interrupt. Refer to the
Chapter 9: I/O
to be read as a logic input.
In the ADCCSR register:
●
Starting the conversion
In the ADCCSR register:
●
When a conversion is complete:
●
●
A read to the ADCDRH or a write to any bit of the ADCCSR register resets the EOC bit.
To read the 10 bits, perform the following steps:
1.
2.
3.
The data is not latched, so both the low and the high data register must be read before the
next conversion is complete, so it is recommended to disable interrupts while reading the
conversion result.
To read only 8 bits, perform the following steps:
1.
2.
AIN
Select the CS[3:0] bits to assign the analog channel to convert.
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.
The EOC bit is set by hardware.
The result is in the ADCDR registers.
Poll the EOC bit.
Read the ADCDRL register.
Read the ADCDRH register. This clears EOC automatically.
Poll the EOC bit.
Read the ADCDRH register. This clears EOC automatically.
is the maximum recommended impedance for an analog input signal. If the impedance
characteristics.
ports. Using these pins as analog inputs does not affect the ability of the port
AIN
AIN
) is greater than V
) is lower than V
Doc ID 13829 Rev 1
SSA
AREF
(low-level voltage reference) then the
(high-level voltage reference) then the
10-bit A/D converter (ADC)
Section 19:
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