ST com STM32C0 Interconnect Matrix Instructions
- June 8, 2024
- ST com
Table of Contents
ST com STM32C0 Interconnect Matrix
STM32C0 – Interconnect Matrix (IMX)
Hello and welcome to this presentation of the STM32 Interconnect Matrix. It covers the main features of this matrix, which is widely used to connect various internal peripherals between each other.
Overview
- Provides direct connections between peripherals
The Interconnect Matrix integrated inside STM32 products provides direct connections between peripherals. Applications benefit from these interconnections to ensure time-predictable operations, to decrease power consumption by avoiding complex management of peripheral communications through reading/writing registers using CPU instructions and, in some cases, to reduce the need to loop the signal from a source to a destination through dedicated GPIOs.
Key features
- Direct, autonomous connections between peripherals
- Removes latency induced by software handling
- Saves CPU resources
- Removes the need for looping signals through dedicated GPIOs
- Can operate during Sleep low-power mode
The Interconnect Matrix offers two main features. First, it ensures direct and autonomous connections between peripherals, allowing to remove latency in regards to software handling, thus saving GPIO and CPU resources. Secondly, the interconnection between peripherals operate during sleep mode.
Sources and destinations
Plenty of interconnect possibilities available
- This slide indicates the list of source and destination peripherals.
- Source peripherals are EXTIs, timers, USARTs, analog IPs, clocks, RTC and System Error.
- Destination peripherals are timers, Infrared Interface, analog IPs and DMAMUX.
- The interconnect matrix is further described in the STM32C0 Reference Manual.
Application examples
This slide and the next one describe the various possible uses for the interconnect matrix:
- Synchronizing or chaining timers, for example allowing a master timer to reset or trigger a second slave timer
- Triggering an ADC through a timer or EXTI event
- Triggering a timer through an ADC watchdog signal when a predefined threshold value is crossed by the analog input
- Calibrating HSI and LSI clocks, for example measuring the external oscillator LSE frequency by a timer clocked by the calibrated internal oscillator.
Other use cases
- Monitoring the temperature of a connected internal temperature sensor or VREFINT
- Protecting timer-driven power switches through the direct connection of System Error signals to the timer break input
- Infrared pulse modulation signal waveform generation using 2 timers
- Triggering a DMA data transfer by a timer.
Timer synchronization example
- Timer 3 can act as a prescaler for Timer 1
This slide shows a simple example of timer synchronization. The Timer 3 is used as the Master Timer and can reset, start, stop or clock the Timer 1 configured in Slave mode. In this example, Timer 3 is clocking the Timer 1 so that it acts as a prescaler for Timer 1. The Master Mode Selection field allows selected information to be sent in master mode to slave timers for synchronization (TRGO): reset, enable, update, compare. In this example, the update option is selected. The Slave Mode Selection field configures the slave mode operation: disabled, encoder, reset, gated, external clock or combined reset. In this example, the external clock mode is selected.
Low-power modes
Peripherals can be interconnected using the Interconnect Matrix even when the circuit is in a low-power sleep mode. Regarding the STM32C0, all supported interconnections between peripherals are functional in both run and sleep modes.
References
- For more details, please refer to:
- Reference manuals for STM32C0 microcontrollers
- Peripherals presentations linked to this IMX peripheral
- Timers (TIM)
- Analog-to-Digital Converter (ADC)
- Extended interrupts and event Controller (EXTI)
- DMA Request Multiplexer (DMAMUX)
- Infrared Interface (IRTIM)
- Reset and Clock Control (RCC)
- Real-Time Clock (RTC)
For more details about the Interconnect Matrix, refer to the reference manual for STM32C0 microcontrollers. Refer also to the following presentations for more information if needed:
- Timers (TIM)
- Analog-to-Digital Converter (ADC)
- Extended interrupts and event Controller (EXTI)
- DMA Request Multiplexer (DMAMUX)
- Infrared Interface (IRTIM)
- Reset and Clock Control (RCC)
- Real-Time Clock (RTC)
Thank you
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