
SP37
Tire Pressure Monitoring Sensor
ROM Library Functions
ROM Library Function Guide
48
Revision 1.0, 2011-12-15
2.4.5
Outputs
2.4.6
Resource Usage
Table 27
Meas_Acceleration: Output values
Register/ Address
Type
Name
Description
R7
unsigned char StatusByte
0000.0000
B
: Success
xxxx.xxx1
B
: Underflow of ADC Result
1)
xxxx.xx1x
B
: Overflow of ADC Result
xxxx.x1xx
B
: Sensor Fault Wire Bond Check
xxxx.1xxx
B
: Sensor Fault Diagnosis Resistor
xxx1.xxxx
B
: VMIN warning
1) If the acceleration measurement result is within the input range for which its accuracy is specified (e.g. -115 g - 115 g), then
the ADC underflow/overflow condition is due to a measurement failure and the measurement results are not valid.
Otherwise, if the acceleration measurement result is outside of this input range, then the ADC underflow/overflow bits and
the acceleration measurement results may be ignored.
*Acce0
signed int
Compensated
Acceleration
If Input Bit SensorConfig.6[RAW] == 0:
8000
H
= -2048.0 g
0000
H
= 0.0 g
7FFF
H
= 2047.9375 g
( = 2048 g - 1 LSB where 1 LSB = 1/16 g)
If Input Bit SensorConfig.6[RAW] == 1:
8000
H
since no compensation is performed
*Acce1
signed int
Raw Acceleration
Data
10 Bit ADC Result Value:
0000.00xx.xxxx.xxxx
B
*Acce2
Singed int
Raw Temperature
If Input Bit SensorConfig.6[RAW] == 0:
16 Bit scaled signed ADC Result Value
If Input Bit SensorConfig.6[RAW] == 1:
8000
H
since no temperature measurement is
performed
Table 28
Meas_Acceleration: Resources
Type
Used or Modified
Registers
R0, R1, R2, R3, R4, R5, R6, R7
SFR
ACC, B, CFG0
, CFG1, CFG2, DIVIC, DPH, DPL, PSW, TCON
, TH0
TMOD
1)
1) Only affected if more than 1 sample is taken
Stack
13 Bytes
2)
2) Two additional bytes, not included here, are needed to call the library function