Samsung 8-Bit CMOS Microcontroller, S3C9228/P9228 user manual Block Diagram

S3C9228/P9228 A/D CONVERTER

Conversion Data Register ADDATAH/ADDATAL

D1H/D2H, Page 0, Read Only

MSB .9 .8 .7 .6 .5 .4 .3 .2

LSB (ADDATAH)

MSB

-

-

-

-

-

-

.1

.0

LSB (ADDATAL)

Figure 14-2. A/D Converter Data Register (ADDATAH/ADDATAL)

INTERNAL REFERENCE VOLTAGE LEVELS

In the ADC function block, the analog input voltage level is compared to the reference voltage. The analog input level must remain within the range VSS to VDD.

Different reference voltage levels are generated internally along the resistor tree during the analog conversion process for each conversion step. The reference voltage level for the first conversion bit is always 1/2 VDD.

BLOCK DIAGRAM

				ADCON.2-.1
	ADCON.4-5
(Select one input pin of the assigned pins)				Clock	To ADCON.3
				Selector	(EOC Flag)
		ADCON.0
		(AD/C Enable)
		M	Analog	Successive
Input Pins		-
			Comparator
				Approximation
AD0-AD3	.	U
(P1.0-P1.3)		+		Logic & Register
	.	X
	.
		ADCON.0
		(AD/C Enable)
	P1CON
(Assign Pins to ADC Input)			VDD	Conversion Result
		10-bit D/A
				(ADDATAH/ADDATAL,
		Converter
			VSS	D1H/D2H, Page 0)

Figure 14-3. A/D Converter Functional Block Diagram

14-3