AN1740 Freescale Semiconductor / Motorola, AN1740 Datasheet - Page 70

• Manufacturer Part Number: AN1740
• Description: Applications Using the Analog Subsystem on MC68HC05JJ/JP Series Microcontrollers
• Manufacturer: Freescale Semiconductor / Motorola

Application Note
70
SAVE RESULT AS V
SAVE RESULT AS V
ON REFERENCE VOLTAGE
ON REFERENCE VOLTAGE
ON UNKNOWN VOLTAGE
ON UNKNOWN VOLTAGE
MAKE A/D CONVERSION
MAKE A/D CONVERSION
MAKE A/D CONVERSION
MAKE A/D CONVERSION
SAVE RESULT AS 2V
SAVE RESULT AS 2V
SAVE RESULT AS V
SAVE RESULT AS V
ADD V
ADD V
WITH INV BIT = 0
WITH INV BIT = 1
WITH INV BIT = 0
WITH INV BIT = 1
READINGS
READINGS
REFA
BEGIN
INA
Figure 29. Flowchart for Calculating A/D Results
AND V
AND V
REFA
REFB
REFB
INB
INA
INB
Freescale Semiconductor, Inc.
REF
IN
For More Information On This Product,
Go to: www.freescale.com
MAKE A/D CONVERSION
MAKE A/D CONVERSION
SAVE RESULT AS V
SAVE RESULT AS V
SAVE RESULT AS 2V
ADD V
ON V
ON V
WITH INV BIT = 0
WITH INV BIT = 1
READINGS
SS
SS
SSA
OMIT THIS STEP IF
RATIOMETRIC RESULTS
ARE DESIRED
VOLTAGE
VOLTAGE
AND V
SSB
SSA
SSB
SS
SAVE RESULT AS 2V
CONVERTED VALUE OF
ASSUMED VALUE FOR
MULTIPLY RESULT BY
SAVE RESULT AS V
SAVE RESULT AS V
UNKNOWN VOLTAGE
2V
2V
2V
STORED IN V
RESULT BY 2
SS
IN
SUBTRACT
SUBTRACT
SS
V
FROM 2V
REF
FROM 2V
DIVIDE
DIVIDE
FROM 2V
- V
SS
REF
REF
IN
IN
REF
IN
IN
MOTOROLA
AN1740