Rev. 1.10
138
October 23, 2020
Rev. 1.10
139
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
ADCEN
START
ADBZ
SACS[3:0]
(SAINS[3:0]=0000B)
off
on
off
on
t
ON2ST
t
ADS
A/D sampling time
t
ADS
A/D sampling time
Start of A/D conversion
Start of A/D conversion
Start of A/D conversion
End of A/D
conversion
End of A/D
conversion
t
ADC
A/D conversion time
t
ADC
A/D conversion time
t
ADC
A/D conversion time
0011B
0010B
0000B
0001B
A/D channel
switch
A/D Conversion Timing – External Channel Input
Summary of A/D Conversion Steps
The following summarises the individual steps that should be executed in order to implement an A/D
conversion process.
• Step 1
Select the required A/D conversion clock by properly programming the SACKS2~SACKS0 bits
in the SADC1 register.
• Step 2
Enable the A/D converter by setting the ADCEN bit in the SADC0 register to “1”.
• Step 3
Select which signal is to be connected to the internal A/D converter by correctly configuring the
SAINS and SACS bit fields.
Select the external channel input to be converted, go to Step 4.
Select the internal analog signal to be converted, go to Step 5.
• Step 4
If the A/D input signal comes from the external channel input selected by configuring the SAINS
bit field, the corresponding pin should first be configured as an A/D input function by configuring
the relevant pin function control bits. The desired external channel input should be selected by
configuring the SACS field. After this step, go to Step 6.
• Step 5
If the A/D input signal is selected to come from the internal analog signal, the SAINS field
should be properly configured and then
the external channel analog input will automatically be
disconnected
regardless of the SACS bit field value
. After this step, go to Step 6.
• Step 6
Select A/D converter output data format by configuring the ADRFS bit in the SADC0 register.
• Step 7
Select the A/D converter reference voltage source by configuring the SAVRS bit field.
Select the PGA input signal and the desired PGA gain if the PGA output voltage, V
R
, is selected
as the A/D converter reference voltage.
• Step 8
If A/D c
onverter interrupt is used, the interrupt control registers must be correctly configured to
ensure the A/D converter interrupt function is active. The master interrupt control bit, EMI, and
the A/D converter interrupt bits, ADE, must both set high in advance.