MC9S08GW64
NXP
The MC9S08GW64 provides a low-cost SOC (System-on-Chip) platform for e-meter applications.
Application NoteNxp
IRTC Compensation and 1 Hz Clock Generation
Technical guide on compensating the Independent Real-Time Clock (IRTC) and generating a precise 1 Hz calibration clock on the NXP MC9S08GW64 SoC for e-metering applications.
Overview
This application note describes methods for compensating the Independent Real-Time Clock (IRTC) module in the NXP MC9S08GW64 SoC, a platform designed for electronic metering. It explains how to utilize the IRTC_COMPEN register to adjust for crystal oscillator frequency variations caused by temperature or aging by adding or removing clock cycles. The document covers compensation intervals from 1 to 255 seconds and provides calculation examples for minimizing timing errors. Furthermore, it details a solution using the FlexTimer Module (FTM) to generate a high-precision 1 Hz clock with a 50% duty cycle by leveraging the bus clock and averaging compensation across each second in the interval.
Use Cases
- Electronic power metering (e-meters)
- Precision timekeeping in low-cost SoCs
- Crystal frequency temperature compensation
- Generating stable calibration signals for timing modules
Topics
NXP
MC9S08GW64
IRTC
Real-Time Clock
Clock Compensation
1 Hz Clock Generation
FlexTimer Module
FTM
E-meter
Crystal Oscillator Calibration
RTCCLKOUT
Referenced Parts
| MC9S08GW64 | NXP | The MC9S08GW64 provides a low-cost SOC (System-on-Chip) platform for e-meter applications. |