z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 346

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Internal Precision Oscillator
Operation
PS022006-0207
The Internal Precision Oscillator (IPO) is designed for use without external components.
Nominal untrimmed accuracy is approximately ±30%. You can manually trim the
oscillator to achieve a ±4% frequency accuracy over the operating temperature and supply
voltage range of the device.
The IPO features include:
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The internal oscillator is an RC relaxation oscillator and has its sensitivity to power
supply variation minimized. By using ratio tracking thresholds, the effect of power
supply voltage is cancelled out. The dominant source of oscillator error is the absolute
variance of chip level fabricated components, such as capacitors. An 8-bit trimming
register, incorporated into the design, allows compensation of absolute variation of
oscillator frequency. After it is calibrated, the oscillator frequency is relatively stable and
does not require subsequent calibration.
By default, the oscillator is configured through the Flash Option bits. However, the user
code overrides these trim values as described in
page 289.
Two frequencies are chosen for the oscillator: 5.5296 MHz and 32 kHz. The
frequency is selected by the OSCSEL bits in the
Nominal ±30% accuracy without trim or manually trim the oscillator to achieve a ± 4%.
On-chip RC oscillator which does not require external components.
Typical output frequency of 5.5296 MHz or 32 kHz.
Trimming possible through Flash option bits with user override.
Eliminates crystals or ceramic resonators in applications where high timing
accuracy is not required.
P R E L I M I N A R Y
Option Bit Configuration By Reset
Oscillator Control Register
Internal Precision Oscillator
Product Specification
ZNEO
™
Z16F Series
on page 329.
on
332