Lesson 1
1. Compared with personal computers (PC), embedded systems have many different characteristics. The following is not a feature of the embedded system is (D).
A) Embedded systems are closely integrated with specific applications and have strong specificity.
B) Embedded systems are usually contained in non-computer equipment (systems), which are concealed.
C) The software and hardware resources of embedded systems are often strictly limited.
D) Embedded systems have lower performance and cheaper prices
[Analysis]: Compared with the personal computers that people use daily, embedded systems have many different characteristics. 1) Dedicated type, embedded system is closely integrated with specific applications, and has a strong dedicated type; 2) Concealment, embedded system is usually always a part of non-computer equipment (system), they are hidden in its internal, not for People know; 3) Resource constraints, embedded systems usually require miniaturization, light weight, low power consumption and low cost, so their software and hardware resources are strictly limited; 4) High reliability; 5) Real-time; 6) Software Curing. In summary, option D is not a feature of embedded systems.
2. The CPU in the embedded system has some characteristics different from the CPU used in the general-purpose computer. The following is not its characteristic (C).
A) Support real-time processing
B) Low power consumption
C) High main frequency
D) Integrated test circuit
[Analysis]: CPU in embedded system generally has 4 characteristics: 1) Support real-time processing; 2) Low power consumption; 3 ) The structure is expandable; 4) The test circuit is integrated. Therefore, this question is C.
3. The English abbreviation of the system-on-chip used by the embedded system is SoC. The error in the SoC description below is (D).
A) SoC is also called system-level chip, it is the product of the improvement of electronic design automation level and the rapid development of integrated circuit manufacturing technology.
B) SoC chip contains both digital circuits, analog circuits, and even digital/analog Hybrid circuit and radio frequency circuit
C) SoC integrates almost all the functions of the embedded system in one chip, a single chip can realize data collection, conversion, storage, processing and I/O and other functions
D) SoC design Manufacturing is very difficult and has not been widely used.
[Analysis]: With the improvement of electronic design automation and the rapid development of VLSI manufacturing technology, semiconductor processing has entered the era of deep submicron from micron and sub-micron, and on a single chip Hundreds of millions or even billions of transistors can be integrated, so that all the circuits of a computer or some other electronic system can be integrated on a single chip, which is a so-called system-on-chip. The SoC chip contains both digital circuits, analog circuits, and even digital/analog hybrid circuits and radio frequency circuits. Since the SoC integrates almost all the functions of the embedded system in a chip, a single chip can realize multiple functions such as data collection, conversion, storage, processing and I/O. At present, most 32-bit embedded processing chips are SoC, and SoC has gradually become the mainstream development trend of integrated circuit design. In summary, the D option is incorrect.
4. The following statement is correct (B)
A. The embedded system is not a computer system.
B. MP3 player is soft real-time.
C. The resource limitation of the embedded system is that the volume of the embedded system is too small.
D. The development and debugging of embedded systems are usually easier than general-purpose computers.
Embedded systems usually require miniaturization, light weight, low power consumption and low cost, so their software and hardware resources are strictly limited;
5. Usually the 32-bit microprocessor refers to (C)
A. The width of the address bus is 32 bits. The length of the processed data can only be 32 bits
C. The word length of the CPU is 32 bits. The number of general registers is 32
6. The architecture that divides the cache into instruction cache (I Cache) and data cache (D Cache) is (B)
A. Von Neumann structure B. Harvard structure
C. RISC D. CISC
7. Embedded applications usually consider running speed optimization and code size optimization, which is determined by the embedded system (C)
A.
B. Determined by specific characteristics
C. Determined by the characteristics of the computer system .
D. Resource-constrained characteristics . Determined by the characteristics of power constraints
8. Which of the following is not a feature of the embedded operating system (C)
A. Streamlined kernel B. Strong specificity C. Powerful function D. High real-time
9. The operation result of 0x07&0x11 is (A)
(A) 0x01 (B) 0x11
© 0x17 (D) 0x07
10. Store a 32-bit unit of four bytes from 0x3162465 to 2000H～2003H. If stored in big-endian mode, the content of the 2000H storage unit is (D).
A, 0x21 B, 0x62 C, 0x65 D, 0x03
11. In addition to being a general-purpose register, register R13 can also be used as (C).
A. Program counter B, link register C, stack pointer register D, base address register
12. In addition to being a general-purpose register, register R14 can also be used as (B)
A. Program counter B. Link register C. Stack pointer register D. Base address register
13. Compared with a PC system, which of the following is not a unique feature of an embedded system (C)
A, the system core is small B, the specificity is strong C, the multitasking can be performed D, the system is simplified
14. Regarding the working mode of the ARM processor, the following statement is wrong (D).
A) User mode is the normal program execution mode
B) Fast interrupt mode is used to process high-speed interrupts, used for high-speed data transmission or channel processing
C) Management mode is used for operating system protection mode, processing soft interrupts
D) System mode is used for processing unintended Defined instruction trap
[Analysis]: ARM processor has a variety of working modes, among which user mode (usr), ARM processor normal program
execution state system mode (sys), runs privileged operating system tasks; fast interrupt mode ( fiq), supports high-speed data transmission or channel processing; management mode (svc), operating system protection mode. In addition, there are data access termination mode (abt), interrupt mode (irq), and undefined instruction termination mode (und). In summary, item D is wrong, so choose D
15. In the embedded ARM processor, which interrupt mode has the highest priority (A)
A. Reset B. Data abort C. FIQ D. IRQ
16. In the ARM processor, the ___________ register includes a global interrupt prohibition bit, which can be turned on or off by controlling the interrupt prohibition bit. (A)
A. CPSR B. SPSR C. PC D. IR
17. Among the various modes of the following ARM processors, the __D___ mode has its own independent R8-R14 registers. (D)
A, system mode (System) B, termination mode (Abort)
C, interrupt mode (IRQ) D, fast interrupt mode (FIQ)
18. The minimum hardware system of the embedded system does not include (C)
A, clock system B, power supply system (power supply)
C, memory system D, reset and its configuration system
19. The requirements of embedded system software are different from those of desktop general-purpose computers. Its characteristics are mainly (ACD)
A, software requires solid-state storage B, programming in a process-oriented language
C, software code requires high efficiency and high reliability ; D. System software (OS) has higher real-time requirements.
20. Due to some kind of strong interference, the program "runs away", which work mode the ARM processor is most likely to enter (D)
A, management mode B, data access termination mode
C, system mode D, undefined instruction abort mode
21. The description of the abnormality of the ARM processor is incorrect (C)
A. The reset belongs to the abnormality B, the division by zero will cause the abnormality
C, all the abnormalities must be returned D, the external interruption will cause the abnormality
22. Which of the following working modes does not belong to the ARM privilege mode (A).
A, user mode B, management mode C, soft interrupt mode D, FIQ mode
23. The following statement about the CPSR register of the ARM processor is wrong (D).
A) CPSR records the working status of ARM
B) CPSR determines ARM working mode
C) CPSR can set whether to allow external interrupts and fast interrupts
D) CPSR is the control register of ARM
[Analysis]: The CPSR register of the ARM processor is the program status register , Including condition code flags, interrupt prohibition bits, current processor mode and other status and control information. So choose D for this question.
24. Regarding the exception of the ARM processor, the following statement is wrong (B).
A) The highest reset exception level
B) FIQ is an external interrupt exception
C) Each exception interrupt vector occupies 4 bytes
D) Different types of exception interrupts have different interrupt service routine entry addresses
[Analysis] ARM has seven exception types, reset Exception, data access abort exception, fast interrupt request exception (FIQ), general interrupt request (IRQ), prefetch instruction exception, software interrupt exception, undefined exception. Each abnormal interrupt vector occupies 4 bytes. Different types of abnormal interrupts have different interrupt service routine entry addresses, and the reset exception level is the highest. So choose B for this topic.
When an exception occurs, the ARM processor automatically updates the PC to the interrupt entry address in the vector table. The processor suspends the execution of normal instructions, refreshes the pipeline again, and starts to load exception handling instructions for execution.
The vector table generally stores the jump address.
Each vector table entry contains a form of branch instruction pointing to the start of a specific routine:
Reset the position of the first instruction that needs to be executed when the vector processor is powered on. This instruction will jump to the initialization code segment to perform the system initialization function.
Undefined instruction vector When the processor cannot decode an instruction
Software interrupt vector When the processor executes the SWI instruction, the SWI instruction is often used to call the operating system API and switch from the user mode to the kernel mode.
Prefetch termination vector When the processor tries to fetch an instruction from an unauthorized address, the actual exception occurs in the pipeline decoding stage.
Data termination vector when the processor tries to fetch data from an unauthorized address. Similar to prefetch termination.
Interrupt request vector When the peripheral sends a request and interrupts the processor's normal execution flow, only when the I flag bit is not masked in the CPSR.
The fast interrupt request vector is similar to the interrupt request. It is reserved for hardware peripherals that need fast response, only when the F flag bit in CPSR is not masked.
What are the main components of the embedded development environment?
Embedded system development requires cross-compilation and online debugging development environment, mainly including
Host computer
Target computer (evaluation circuit board)
JTAG-based ICD emulator, or debugging monitoring software, or in-circuit emulator ICE
Cross compiler and linker running on the host computer, and development tool chain or software development environment
Embedded operating system