Startxtalosc(); Description; Actions; Prototype - Infineon SP37 Function Manual

2.15

StartXtalOsc()

2.15.1

Description

This function enables the crystal oscillator clock and delays for a defined amount of time. The delay time should
be long enough that the crystal oscillator is stable, which is determined by the crystal startup time (see [1]). The
minimum/maximum tolerance of the delay time may be derived by considering the tolerance of the
12 MHz RC Oscillator (see [1]).
2.15.2

Actions

• Enable the crystal oscillator clock
• Wait in IDLE for set Delay time
2.15.3

Prototype

signed char StartXtalOsc(unsigned char Delay)
2.15.4

Inputs

Table 70 StartXtalOsc: Input Parameters
Register / Address
R7
2.15.5

Outputs

Table 71 StartXtalOsc: Output values
Register/Address
R7
2.15.6

Resource Usage

Table 72 StartXtalOsc: Resources
Type
Registers
SFR
Stack
1) Two additional bytes, not included here, are needed to call the library function
ROM Library Function Guide
Type Name
unsigned char Delay
Type Name
signed char StatusByte
Used or Modified
R7
ACC, B, CFG0, DPTR, DIVIC, PSW, REF, TCON, TH0, TL0, TMOD
1)
0 Bytes
Tire Pressure Monitoring Sensor
Description
Delay time to wait in IDLE after XTAL is enabled.
Duration[µs] = Delay x 42.67[µs]
Description
StatusByte:
0: XTAL started and delay passed
-1: XTAL already on (no action)
75
SP37
ROM Library Functions
Revision 1.0, 2011-12-15