What type of embedded sytem is used in a mobile phone(cell phone)?

Question

What type of embedded system is used in a mobile?Is it a microcontroller, FPGA or a DSP

According to my understanding the basic and simple mobile phones like nokia 3310 used microcontroller since those phones had relatively simple applications and today android phones like samsung galaxy use DSP or FPGA . Or is it combination of microcontroller and DSP?

Update: Based upon latest answers, i am unable to find any mention of basic simple phone like Nokia 3310 in answers here. If possible, please also mention the type of embedded systems of basic simple phone like Nokia 3310 along mentioning type of embedded system of today android smart phones

Answer 1

The usual terminology is "SoC" for "system-on-a-chip". This includes a CPU and a whole bunch of other stuff.

Qualcomm seem to like calling theirs a "platform", but that's a really generic term. You can see from that link that a single package/chip contains a CPU, GPU, a RF modem (which will contain a powerful DSP), a number of other DSPs dedicated to Wifi etc, and an image DSP to take data from the camera.

It is definitely not an FPGA, that's not really suitable for mass-market products.

Edit in response to update: the current Nokia 3310 https://en.wikipedia.org/wiki/Nokia_3310_(2017) is listed as having a MediaTek MT6260, which also counts as a "SoC".

We can see from the MT6260 datasheet:

MT-6260 consists of the following subsystems:

1. Microcontroller Unit (MCU) subsystem : Includes an ARM7EJ-STM RISC processor and its accompanying memory management and interrupt handling logics
2. Digital Signal Processor (DSP) subsystem: Includes a DSP and its accompanying memory, memory controller and interrupt controller
3. MCU/DSP interface: Junction at which the MCU and the DSP exchange hardware and software information

I guess that answers your question precisely; it's a single chip, which contains an ARM processor deemed to be a "microcontroller", AND a DSP for the modem.

Answer 2

The “heart” of a mobile phone will usually be an SoC, which is a combination of a CPU (usually with multiple cores), a GPU (ditto), and a number of peripherals like interfaces to the screen, to the touch screen, to the various sensors, etc.

Most SoCs for mobile phone are built around ARM cores, usually of the A family.

There will also be RAM and flash, which may be built into the SoC or be external.

Then there will be Wifi, BLE and cellular models, which again may be integrated into the SoC or external.

Some of the main producers of SoCs for mobile phones are:

• Apple for their own devices
• Samsung, mostly for their own devices, but they also sell some models to third parties
• Qualcomm
• MediaTek
• Allwinner
• …

Qualcomm is probably the largest provider of cellular modems, but others play in that field as well.

It’s uncommon to find generic programmable DSPs, more often there will be chips (or components inside a chip) which are designed to perform specific tasks.

Answer 3

It might be better to pick a specific cell phone and look into it a bit more deeply. For example, the iPhone X (iPhone 15 is about to come out so it's back quite a few generations but still usable).

You can google (model) + teardown and get analysis of the circuitry. The iPhone X uses an A11 "Bionic" "10nm" system-on-chip (SOC) which has an 6-core ARM-based CPU and some coprocessors such as a 3-core graphics unit. As with (probably) all cell phones, there is no way to put enough memory (RAM or flash) to be acceptable for a flagship phone onto a single chip with the CPU and other logic, but they did the next-best thing and stacked a 3G RAM chip on top of the SOC chip, using "package-on-package" technology. Flash memory (64G or more) is external to that stack.

While "System-on-chip" is suitably vague to be correct in all cases, the main CPU in a cell phone won't be a microcontroller because of the memory requirements and die size limitations, it will be a microprocessor (the distinction being external memory and perhaps memory management unit, a somewhat hazy difference and depending on who you are talking to).

You can even find a pdf schematic of many cell phones (92 pages long in the case of iPhone X).

Answer 4

Mobile phones need to consume as little power as possible for thermal performance and battery life. Therefore they need to implement dedicated hardware for DSP, de-/encoders, buses etc. That hardware may be part of the main CPU or another chip. The main CPU would run on low clock speed or be at sleep mode while the dedicated HW does as much as possible. The CPU can react to interrupts when intervention is needed.

Usually the processors are usually partially or completely custom to fit perfectly to application and the details are not revealed. Along the CPU a customized ASIC would be used, rather than off-the-shelf FPGA.

Answer 5

Non-smart phones tended to contain an extra low-powered processor that is responsible for charge control, timer uses (so the alarm clock and similar features work even when the phone is switched off) and basic controls. This one is always-on and is responsible for hacked phones being unsafe as long as power is available, even if the phone appears to be powered off.

I was pretty surprised at smartphones not doing alarm clock duty any more when switched off, so that architecture seems to have changed.