explain
Stm32l4r5xx, stm32l4r7xx and stm32l4r9xx devices are a family of ultra-low power microcontrollers (stm32l4 + Series) based on high-performance arm ® Cortex ®- M432-bit RISC core. Their operating frequency is as high as 120 MHz.
The core of cortex-m4 has a single precision floating point unit (FPU), which supports all arms ® Single precision data processing instructions and all data types. The cortex M4 core also implements a complete set of DSP (digital signal processing) instructions and a memory protection unit (MPU), which improves the security of the application.
These devices embed high-speed memory (2 megabytes of flash memory and 640 kilobytes of SRAM), flexible external memory controller (FSMC) for static memory (for devices with 100 pins and more packages), two o0tospi flash interfaces (all packages), and extensive enhanced I / O and connection to two APB buses, two AHB buses and a 32-bit multi AHB bus matrix.
Stm32l4rxxx device embeds several embedded flash memory and SRAM protection mechanisms: read protection, write protection, proprietary code read protection and firewall.
These devices provide fast 12 bit ADC (5msps), two comparators, two operational amplifiers, two DAC channels, an internal voltage reference buffer, a low-power RTC, two general-purpose 32-bit timers, two 16 bit PWM timers dedicated to motor control, seven general-purpose 16 bit timers and two 16 bit low-power timers. The device supports four digital filters for external sigma delta modulator (dfsdm). In addition, 24 more capacitive sensing channels are available.
They also have standard and communication interfaces, such as:
• four I2C
• three SPIs
• three USARTs, two UARTS and one low power UART
• two audits
• one SDMMC
• one can
• one USB OTG full speed
• camera interface
• dma2d controller
When using the internal LDO regulator, the VDD power supply temperature of - 40 to + 85 ° C (+ 105 ° C) and - 40 to + 125 ° C (+ 130 ° C) is 1.71 to 3.6V, and when using the external SMPS power supply, it is 1.05 to 1.32vvdd12 power supply. A comprehensive set of energy-saving models allows the design of low-power applications.
Support some power supplies, such as analog power input of ADC, DAC, OPAMP and comparator, usb3 3V dedicated power input and 14i / O, which can be supplied to 1.08v. The Vbat input allows backup of RTC and backup registers. When connected to an external SMPS, a dedicated vdd12 power supply can be used to bypass the internal LDO regulator.