3
\$\begingroup\$

STM32 and STM8 devices have some types:

  • Low density devices
  • Medium density devices
  • High density devices

About what "density" mean? About quantity of periphery or about quantity of flash or something else?

\$\endgroup\$
6
\$\begingroup\$

They're arbitrary terms used by ST to distinguish different lines of MCUs within a series. Generally speaking, all of the parts within a line will have all the same peripherals and features; they will differ only in the amount of RAM and flash memory they have, and in packaging.

For instance, here's how ST breaks down the STM32F103 family:

enter image description here

The terms "value line" and "connectivity line" also appear in some series; those are also treated as lines.

|improve this answer|||||
\$\endgroup\$
  • \$\begingroup\$ It's not quite right same peripherals and features. High density devices have lager set of peripherals and more features. And for medium and low density devices this set decreases. Just open one of Reference manuals and see this differents. For this one DAC, AES, USART2, USART3, TIM5, SPI2 not available for low-density devices. Other features as clock dividers bitwidth are different in different density devices. \$\endgroup\$ – imbearr Jul 30 '16 at 9:31
  • \$\begingroup\$ @imbearr I think you're misreading my answer. What I'm saying is that all "high density" devices within a series have the same peripherals and features. They will still differ from devices in other lines, like the corresponding "medium density" parts. \$\endgroup\$ – duskwuff -inactive- Jul 30 '16 at 15:39
  • \$\begingroup\$ @duskwuff, could you give example of such two devices from one line (high or another) with same periferals and features. I doubt that such exist. As I understand this grades (high/medium/low) can be applied to one family (for ex. STM8Lx51) and it can be used only for understand power of devices. \$\endgroup\$ – imbearr Jul 30 '16 at 15:50
  • \$\begingroup\$ @imbearr STM32F103C8 and STM32F103RB, for instance. Both members of the STM32F103 medium-density line; they differ only in flash size and pin count. \$\endgroup\$ – duskwuff -inactive- Jul 30 '16 at 15:58
  • \$\begingroup\$ @duskwuff, you right. I was inattentive when read you answer. \$\endgroup\$ – imbearr Jul 30 '16 at 16:50
-1
\$\begingroup\$

About the reference guide of STM32F103 Glossary :

• Low-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers where the Flash memory density ranges between 16 and 32 Kbytes.

• Medium-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers where the Flash memory density ranges between 64 and 128 Kbytes.

• High-density devices are STM32F101xx and STM32F103xx microcontrollers where the Flash memory density ranges between 256 and 512 Kbytes.

• XL-density devices are STM32F101xx and STM32F103xx microcontrollers where the Flash memory density ranges between 768 Kbytes and 1 Mbyte.

• Connectivity line devices are STM32F105xx and STM32F107xx microcontrollers.

• Word: data of 32-bit length.

• Half-word: data of 16-bit length.

• Byte: data of 8-bit length.

|improve this answer|||||
\$\endgroup\$
  • \$\begingroup\$ What is the definition of word/half-word/byte doing here? \$\endgroup\$ – dim lost faith in SE Dec 23 '16 at 15:30
-2
\$\begingroup\$

First let’s explain what Low Density and High Density refers to. Using 256MB modules as an example… you would think the 16 chip module would be called the High Density module and the 8 chip version would be the Low Density module… but it’s backwards, isn’t it? The problem is – the density isn’t referring to the number of chips on the module, it refers to the density of the memory units inside the individual chips on the module.

When people talk about a Low Density module, they’re incorrectly abbreviating their speech, and it’s misleading. What they really mean is – it’s a module with Low Density chips. Think of two pepperoni pizzas. On one pizza each slice has 2 pieces of pepperoni. On the other each slice has 4 pieces of pepperoni. The one with 2 pieces per slice is the low density pizza, and the one with 4 pieces per slice is the high density pizza.

This is what it’s like on the RAM modules. The High Density module only needs half as many chips per side because there are more memory slots inside those chips. If you want Low Density chips, you need twice as many, and so modules with Low Density chips cost twice as much. (The labor to build the module from the assembled parts is about the same, regardless.)

|improve this answer|||||
\$\endgroup\$
  • \$\begingroup\$ Thanks, but you don't answer to my question. "Density" is about RAM/FLASH or about periphery or about something else? \$\endgroup\$ – Ilya A Jul 27 '16 at 6:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.