
SP37
Tire Pressure Monitoring Sensor
ROM Library Functions
ROM Library Function Guide
69
Revision 1.0, 2011-12-15
2.12
ADC_Selftest()
2.12.1
Description
The ADC self test is a combination of three measurements that use various channels as input and reference for
the ADC. The output of this function is the delta deviation from the ideal value.
2.12.2
Actions
•
Perform three ADC measurements
•
Calculate delta from ideal value
2.12.3
Prototype
unsigned char
ADC_Selftest
(signed int idata *
Delta
)
2.12.4
Inputs
2.12.5
Outputs
Table 58
ADC_Selftest: Input Parameters
Register / Address
Type
Name
Description
R7
signed int
idata*
Delta
Pointer to an integer array in RAM to receive the
ADC measurement result
Table 59
ADC_Selftest: Output values
Register/ Address
Type
Name
Description
R7
unsigned char StatusByte
0000.0000
B
: Success
xxxx.xxx1
B
: Underflow of ADC Result
xxxx.xx1x
B
: Overflow of ADC Result
*Delta
signed int
idata*
Delta
The ADC can be considered as working when the
value of Delta is b/-6 LSBs after a call of
this function during which the supply voltage was
constant.