This week’s EYE on NPI looks at a new microcontroller series from ST Micro. Yes, last week was also an ST part – but this one popped into my NPI feed and I just thought it was so interesting, ST gets a double-header! The STM32L4P5 series of chips looks like an excellent competitor to the Microchip ATSAMD51 we use so often – with matching-or-better specifications. Let’s take a closer look!
You can get more spec’s about this chip over at ST’s website. Here’s the overview:
The Cortex-M4 core features a single-precision floating-point unit (FPU), which supports all the Arm® single-precision data-processing instructions and all the data types. The Cortex-M4 core also implements a full set of DSP (digital signal processing) instructions and a memory protection unit (MPU) that enhances the application’s security.
These devices embed high-speed memories (up to 1 Mbyte of Flash memory and 320 Kbytes of SRAM), a flexible external memory controller (FSMC) for static memories (for devices with packages of 100 pins and more), two OCTOSPI Flash memory interfaces (for devices with packages of 100 pins or more) and an extensive range of enhanced I/Os and peripherals connected to two APB buses, two AHB buses and a 32-bit multi-AHB bus matrix.
These devices offer two fast 12-bit ADCs (5 Msps), 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 devices support two digital filters for external sigma delta modulators (DFSDMs). In addition, up to 24 capacitive sensing channels are available.
They also feature standard and advanced communication interfaces such as: four I2Cs, three SPIs, three USARTs, two UARTs and one low-power UART, two SAIs, two SDMMCs, one CAN, one USB OTG full-speed, one camera interface and one synchronous parallel data interface (PSSI).
In particular, we like some of the ‘upgrades’ we see compared to other chips – the roomy 320KB RAM, 5 MSPS 12-bit ADCs (that’s the same as a basic pocket oscilloscope!), 9 x 16-bit timers, CAN bus (usually you have to upgrade to get CAN support!), built in op-amps, and… most interesting to me is a built in TFT manager! Not just parallel (6800/8080) style but the ‘real’ 24-bit TFT with HSYNC/VSYNC/CLK signals! Usually you have to go to a Cortex M7 to get something like that included (see the iMX RT or STM32H7 series for example). 24-bit TFT can be easily converted to VGA (using some resistors) or even HDMI using off-the shelf adapter chips so it’s really a neat thing to see.
True TFT output is a rarity because of the frame buffer you normally need. From what ST says in the datasheet the way this is managed in RAM is to have a 8-bit palette of 24-bit colors. So for a classic 4.3″ TFT display that is 480×272 pixels, that would mean 128KB of RAM to address all pixels. A 320×240 display would be only 75KB.
LCD-TFT controller (LTDC)
The LCD-TFT display controller provides a 24-bit parallel digital RGB (red, green, blue) and delivers all signals to interface directly to a broad range of LCD and TFT panels with the following features:
• One display layer with dedicated FIFO (64 x 32-bit)
• Color look-up table (CLUT) up to 256 colors (256 x 24-bit) per layer
• Up to 8 input color formats selectable per layer
• Flexible blending between two layers using alpha value (per pixel or constant)
• Flexible programmable parameters for each layer
• Color keying (transparency color)
• Up to four programmable interrupt events
For now we recommend picking up the STM32L4P5AGI6PU Discovery also known as STM32L4P5G-DK on Digi-Key. Which has a built in debugger/programmer and is directly supported in STM32 Cube IDE.
To see more products in the EYE on NPI series, click here.