ports/psoc6/docs/psoc6: Adding ADC docs for psoc6 port.

Signed-off-by: NikhitaR-IFX <Nikhita.Rajasekhar@infineon.com>

docs/psoc6/quickref.rst

@@ -426,4 +426,48 @@ Methods
 ^^^^^^^
 All the methods(functions) given in :ref:`machine.SPI <machine.SPI>` class have been implemented in this port
 
+ADC (analog to digital conversion)
+----------------------------------
+
+On the PSoC6, a single ADC block with id - '0' is available. The ADC functionality is available on the
+following pins : "P10_0" - "P10_5".
+
+Use the :ref:`machine.ADC <machine.ADC>` class::
+
+    from machine import ADC, Pin
+
+    adc = ADC(Pin("P10_0"))        # create an ADC object on ADC pin
+    val = adc.read_u16()           # read a raw analog value in the range 0-65535
+    val = adc.read_uv()            # read an analog value in micro volts ranging 0.0V - 3.3V
+
+The PSoC6 port also supports :ref:`machine.ADC <machine.ADCBlock>` API to have control over the ADC configuration. Currently 
+PSoC6 supports only 1 12-bit SAR ADC with the following channel to pin mapping and the defaults are set accordingly:
+
++---------+-------+
+| Channel |  Pin  |
++=========+=======+
+|    0    | P10_0 |
++---------+-------+
+|    1    | P10_1 |
++---------+-------+
+|    2    | P10_2 |
++---------+-------+
+|    3    | P10_3 |
++---------+-------+
+|    4    | P10_4 |
++---------+-------+
+|    5    | P10_5 |
++---------+-------+
 
+.. note::
+    Arbitrary connection of ADC channels to GPIO is not supported. Specifying a pin that is not connected to this block, 
+    or specifying a mismatched channel and pin, will raise an exception.
+
+To use the APIs:
+
+    from machine import ADCBlock, Pin
+
+    adcBlock = ADCBlock(0, bits=12)             # create an ADCBlock 0 object
+    adc = adcBlock.connect(0, Pin("P10_0"))     # connect channel 0 to pin P10_0
+    val = adc.read_u16()                        # read a raw analog value in the range 0-65535
+    val = adc.read_uv()                         # read an analog value in micro volts ranging 0.0V - 3.3V