
SP37
Tire Pressure Monitoring Sensor
ROM Library Functions
ROM Library Function Guide
79
Revision 1.0, 2011-12-15
2.17
PLL_Ref_Signal_Check()
2.17.1
Description
This function can be called prior to
routine to test the lowest and highest VCO tuning curves that
are disjoint in terms of operating frequencies. If the PLL Lock Detector indicates lock for both of the disjoint VCO
tuning curves, a malfunction of the Crystal Resonator is most likely the source of the fault.
2.17.2
Actions
•
Select the lowest tuning curve and check the PLL Lock Detector result
•
Select the highest tuning curve and check the PLL Lock Detector result
2.17.3
Prototype
signed char
PLL_Ref_Signal_Check
(void)
2.17.4
Inputs
2.17.5
Outputs
2.17.6
Resource Usage
Table 78
PLL_Ref_Signal_Check: Input Parameters
Register / Address
Type
Name
Description
None
---
---
---
Table 79
PLL_Ref_Signal_Check: Output values
Register/Address
Type
Name
Description
R7
signed char
StatusByte
StatusByte:
0: PLL Reference Signal available
-1: No PLL Reference Signal available
Table 80
PLL_Ref_Signal_Check: Resources
Type
Used or Modified
Registers
R7
SFR
ACC, B, PSW, DIVIC, DPTR
Stack
2 Bytes
1)
1) Two additional bytes, not included here, are needed to call the library function