Key facts
- Brand
- STMicroelectronics
- Model
- STM8L15x
- Category
- microcontrollers
- Documents
- 3
- Languages
- EN
- Last added
- 2012-08-07
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STMicroelectronics STM8L15x/STM8L16x Real-Time Clock Application Note AN3133
The document details the capabilities of the Real-Time Clock (RTC) found in specific STM8L series microcontrollers. Key features include a full-featured calendar tracking time and date, programmable alarms with various masking options, a periodic wakeup unit for low-power operation, smooth digital calibration to adjust clock accuracy, and tamper detection circuits.
The guide provides step-by-step instructions on how to initialize the calendar, program alarms, and configure the auto-wakeup unit. It includes five specific application examples covering calendar/alarm usage, waking from low power modes, periodic event generation, tamper detection, and chronometer functionality.
STMicroelectronics STM8L15x specifications
| Supported Microcontroller Families | medium density STM8L15x and medium+ and high density STM8L15x/16x devices |
|---|---|
| Calendar Format | BCD (binary-coded decimal) |
| Sub-second Resolution Range | up to 0xFFFF or 65535 in decimal |
| Sub-second Adjustment Range | up to 32767 (0x7FFF) sub-seconds |
Source: STMicroelectronics STM8L15x/STM8L16x Real-Time Clock Application Note AN3133
All STMicroelectronics STM8L15x documents by type
How to use the product for one specific task, with worked examples.
Questions answered in these manuals
What microcontrollers does this application note cover?
It covers the real-time clock controller embedded in medium density STM8L15x and medium+ and high density STM8L15x/16x devices.
From: STMicroelectronics STM8L15x/STM8L16x Real-Time Clock Application Note AN3133
Does the RTC calendar support sub-seconds?
Yes, a sub-second field is available on medium+ and high density devices in binary format.
From: STMicroelectronics STM8L15x/STM8L16x Real-Time Clock Application Note AN3133
What are the two methods for calibrating the HSI oscillator?
The first method is based on finding the frequency with the minimum error, and the second consists in finding the maximum allowed frequency error.
What reference sources can be used for HSI calibration?
An accurate reference source such as the LSE frequency provided by an external 32.768 kHz crystal or the 50 Hz/60 Hz of the mains can be used.
What hardware is required to run this application?
The application uses the STM8L-DISCOVERY on-board LEDs, 6-digit/4-bar LCD glass display, and user push-button; no additional components are required.
From: STMicroelectronics AN3269 STM8L15x Power Saving Modes Application Note
How does the application measure current in low power modes?
In low power modes, a counter enabled by the STM8L manages timing while idle. A capacitor stores the measurement charge so the microcontroller can display the value early upon wake-up.
From: STMicroelectronics AN3269 STM8L15x Power Saving Modes Application Note