s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 105

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

ECGST — External Clock Status Bit
10.8.2 Oscillator Trim Register (OSCTRIM)
TRIM7–TRIM0 — Internal Oscillator Trim Factor Bits
Freescale Semiconductor
This read-only bit indicates whether an external clock source is engaged to drive the system clock.
These read/write bits change the internal capacitance used by the internal oscillator. By measuring the
period of the internal clock and adjusting this factor accordingly, the frequency of the internal clock can
be fine tuned. Increasing (decreasing) this factor by one increases (decreases) the period by
approximately 0.2% of the untrimmed oscillator period. The oscillator period is based on the oscillator
frequency selected by the ICFS bits in OSCSC.
1 = An external clock source engaged
0 = An external clock source disengaged
Reset:
Read:
Write:
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
TRIM7
Bit 7
1
Figure 10-5. Oscillator Trim Register (OSCTRIM)
TRIM6
6
0
TRIM5
5
0
TRIM4
4
0
TRIM3
3
0
TRIM2
2
0
TRIM1
1
0
TRIM0
Bit 0
0
Registers
105