Computer Knowledge
Part One: SoC
1. CPU = Arithmetic Unit + Control Unit
2. Graphics Processing Unit (GPU) is also known as display core, visual processor, or display chip. Its purpose is to convert and drive the display information required by the computer system, providing horizontal scanning signals to the monitor and controlling the correct display of the monitor. It is an important component connecting the monitor and the personal computer motherboard.
3. Peripherals: Refers to other components aside from the CPU.
4. SoC (System on Chip): SoC is known as a system-level chip, also referred to as an on-chip system, meaning it is a product, an integrated circuit with a dedicated purpose, containing a complete system and all embedded software content. The CPU connects various external devices through an external bus to form the SoC.
Part Two: Introduction to ARM
On December 5, 1978, physicist Hermann Hauser and engineer Chris Curry founded the CPU Company in Cambridge, England, mainly supplying electronic devices to the local market.
In 1979, the CPU Company was renamed Acorn Computers.
Initially, Acorn planned to use Motorola’s 16-bit chips but found them too slow and expensive. They turned to Intel for the design of the 80286 chip but were refused, forcing them to develop their own.
In 1985, Roger Wilson and Steve Furber designed their first generation 32-bit, 6M Hz processor, creating a RISC instruction set computer, abbreviated as ARM (Acorn RISC Machine). This is how the name ARM originated.
On November 27, 1990, Acorn officially reorganized into ARM Computer Company.
In the 1990s, ARM’s 32-bit embedded RISC (Reduced Instruction Set Computer) processors expanded worldwide, leading the field of low-power, low-cost, and high-performance embedded system applications. ARM does not produce or sell chips; it only licenses chip technology.
Since 1983, the ARM cores include ARM1, ARM2, ARM6, ARM7, ARM9, ARM10, ARM11. After ARM11, the processor family adopted the Cortex naming scheme, divided into A, R, and M processors for high, medium, and low levels respectively.
History of Raspberry Pi Development
February 2012: Raspberry Pi Model B
February 2013: Red Chinese version Raspberry Pi Model B
March 2013: Raspberry Pi Model A
July 2014: Raspberry Pi Model B+
November 2014: Raspberry Pi Model A+
February 2015: Raspberry Pi Model 2B
November 2015: Raspberry Pi Zero
February 2016: Raspberry Pi Model 3B
November 2017: Raspberry Pi Zero W
March 2018: Raspberry Pi Model 3B+
Let’s take a look at the specifications of each generation
The first generation Raspberry Pi includes multiple versions: A, A+, B, B+. The most common version in China is the B version, while the A version was not actually released.
The A version is a simplified version of the B version. The first Raspberry Pi released was the B version.
Raspberry Pi B
Specifications:
Broadcom BCM2835
ARM1176JZF-S core (ARM11) 700MHz
Memory: 512MB
Dual-core multimedia coprocessor (using VideoCore IV technology)
1 SD/MMC/SDIO interface, 1 10/100 Ethernet interface, 2 USB host interfaces, 1 3.5mm audio jack, 1 HDMI video interface, 1 RCA video interface, 1 26-pin expansion port (supports SPI, I2C, UART)
In February 2013, the domestic manufacturer Shenzhen Yundong Electronics obtained production and sales rights for this product in China. To distinguish the market, the Raspberry Pi Foundation stipulated that Yundong Electronics must use red PCBs for Raspberry Pi sold in mainland China.
Raspberry Pi A
The Model A can be considered a cheaper version of the Raspberry Pi Model B, lacking a network interface and further reducing memory capacity. The Raspberry Pi A (not released) has 256MB of internal memory and one USB port, without a wired network interface.
Raspberry Pi B+
The “Raspberry Pi B+” version still uses the BCM2835 processor and the same system software as the previous generation Raspberry Pi. Memory remains at 512MB; however, several key components have been improved:
More GPIO pins, 40 pins! (The old version had 26 pins)
More USB interfaces, 4 in total! Improved hot-swapping and overcurrent protection.
Replaced the old SD slot with a Micro SD slot.
Lower power consumption, reduced by 0.5 to 1W.
Audio optimization, the audio circuit uses a dedicated low-noise power supply.
Simpler design, the B+ version aligns the USB interfaces with the edge of the circuit board, removes the AV interface, and adds 4 mounting holes on the main board for easy fixing.
In terms of configuration, the model B+ uses the same BCM2835 chip and 512MB memory as the model B, but compared to its predecessor, the B+ version has lower power consumption and richer interfaces. The model B+ increases the general-purpose input/output pins to 40, and the USB interfaces have increased from 2 in the B version to 4 in the B+ version. Additionally, the model B+ reduces power consumption to 0.5W to 1W, and the old SD card slot has been replaced with a more aesthetically pleasing push-type microSD card slot, while the audio section uses low-noise power supply. In terms of appearance, the USB interfaces have been moved to one side of the main board, the composite video has been moved to the location of the 3.5mm audio jack, and four independent mounting holes have also been added.
Raspberry Pi A+
This new model supports the same MicroSD card reader and 40-pin GPIO connection port as Model B. Other features include Broadcom BCM2385 ARM11 processor, 256MB memory, and HDMI output port. The complete specifications for Model A+ are as follows:
● 700MHz Broadcom BCM2835 processor with 256MB memory
● 40-pin expansion GPIO
● 1 USB 2.0 port
● 4-channel stereo output and composite video port
● Full-size HDMI port
● CSI port for connecting Raspberry Pi camera
● DSI port for connecting Raspberry Pi touchscreen
● MicroSD port for loading the system and storing data
● Micro USB power supply
● Smaller motherboard size and fully compatible with HAT
● Supports 1080P HD video output
Raspberry Pi 2B
Specifications:
Equipped with a 900MHz quad-core processor (900MHz quad-core ARM Cortex-A7 CPU), expected performance is 6 times that of the previous B+ version.
1GB LPDDR2 SDRAM, twice that of the previous B+ version.
Raspberry Pi Zero
Specifications:
Broadcom BCM2835 chip 1GHz ARM11 core (40% faster than Raspberry Pi 1)
512MB LPDDR2 SDRAM
One micro-SD card slot
One mini-HDMI interface, supports 1080p 60hz video output
Micro-USB interface for power and data transfer
1 40Pin GPIO interface, the same as Raspberry Pi A+, B+, and 2B versions (pins are vacant and need to be soldered, making it smaller and easier to package when GPIO is not needed)
Vacant video interface (for connecting TV output video, needs to be soldered)
Smallest Raspberry Pi size ever, 65mm x 30mm x 5mm
Raspberry Pi 3B
Specifications:
64-bit 1.2 GHz ARM Cortex A53 processor, built-in WIFI, compatible with 2.4GHz 802.11 b/g/n; significant improvements in video and 3D performance; supports Bluetooth 4.1 specification. 4 USB 2.0 ports, 10/100 Ethernet, HDMI port, 3.5mm audio port and video output, CSI and DSI camera and display connectors. microSD slot and GPIO slot.
Raspberry Pi Zero W
Specifications: BCM2835, 1GHz, ARM11 CPU 512MB RAM Mini-HDMI interface Micro-USB On-The-Go interface Micro-USB power interface 40-pin GPIO HAT reserved solder interfaces CSI camera soft cable interface 802.11n wireless network support Bluetooth 4.0 support
Raspberry Pi 3B+
Specifications:
1.4GHz 64-bit quad-core ARM Cortex-A53 CPU
Dual-band 802.11ac wireless network card and Bluetooth 4.2
Faster Ethernet (Gigabit Ethernet over USB 2.0)
1G LPDDR2
PoE support (Power-over-Ethernet, with PoE HAT)
Improved PXE network and USB mass storage boot
Next, let’s compare the generations
Differences Between Raspberry Pi Model A and B
Raspberry Pi Model A has 256MB of internal memory, one USB port, and lacks a wired network interface.
Raspberry Pi Model B has 512MB of internal memory, two USB ports, and a 100M wired network interface.
Differences Between Raspberry Pi B and B+
In July 2014, the “Raspberry Pi B+” version was released, still using the BCM2835 processor and the same system software as the previous generation Raspberry Pi. Memory remains at 512MB; however, several key components have been improved:
● More GPIO pins, 40 pins! (The old version had 26 pins)
● More USB interfaces, 4 in total! Improved hot-swapping and overcurrent protection.
● Replaced the old SD slot with a Micro SD slot.
● Lower power consumption, reduced by 0.5 to 1W.
● Audio optimization, the audio circuit uses a dedicated low-noise power supply.
● Simpler design, the B+ version aligns the USB interfaces with the edge of the circuit board, removes the AV interface, and adds 4 mounting holes on the main board for easy fixing.
Raspberry Pi 2 Compared to Previous Generations
● CPU single-thread speed increased by 1.5 times (up by 1.5x)
● Sunspider score increased 4 times (4x faster)
● Based on NEON multi-core video decoding speed increased 20 times (20x faster)
● SysBench overall multi-thread CPU score is 6 times that of the old version (6x)
Differences Between Raspberry Pi 2B and Raspberry Pi B
● Equipped with a 900MHz quad-core processor (900MHz quad-core ARM Cortex-A7 CPU), expected performance is 6 times that of the previous B+ version.
● 1GB LPDDR2 SDRAM, twice that of the previous B+ version.
● Fully compatible with the first generation.
Since the CPU has been upgraded to ARM Cortex-A7, the Raspberry Pi 2 will support running the full range of ARM GNU/Linux distributions, including Ubuntu and even Microsoft’s Windows 10.
Differences Between Raspberry Pi 3B and 2B
In February 2016, the “Raspberry Pi 3B version was released.
● Equipped with a 1.2GHz 64-bit quad-core processor (ARM Cortex-A53 1.2GHz 64-bit quad-core ARMv8 CPU).
● Added 802.11 b/g/n wireless network card.
● Added low-power Bluetooth 4.1 adapter.
● Maximum driving current increased to 2.5A
If you have any questions, you can refer to our video
https://space.bilibili.com/255808664/#/video
If you have any questions, feel free to join our official group for consultation
QQ group: 695558192
