bfo oscillator

latest products, but not long after the listing, was some small factory piracy. Because the technical difficulty of copying a single-chip microcomputer motherboard is not big. These small factories are unable to develop independently, but the product price is half cheap, function and genuine, machine boss naturally like. In order to combat piracy, genuine manufacturers in the program set bugs, any _ you go to piracy, as long as you shop to a certain extent, I will publish bugs, instantly let yo

1. Clock source Three different clock sources can do the system clock (SYSCLK):HSI oscillator Clock: high-speed internal clockHSE oscillator Clock: high-speed external clockPLL ClockTwo x two-level clocksLSI (Low speed internal clock): 32kHz low-speed internal RC (LSI RC) Independent watchdog clock Source, RTC can be used for automatic wake-up stop/Standby mode.LSE (Low Speed external clock): 32.76

RCC Clock module is not good understanding, the first contact I also confused, and I really mastered it is also relatively late, is that I learned to use Register control Development Board to really understand his operating principles and laws, but why I re-revised but placed in the forefront, because this is the whole embedded foundation, beginners are more difficult , but I still want to be able to grasp the best, because the real-time is very important to the embedded system, and the basis is

The PLL is actually a negative feedback system that synchronizes the clock on the circuit with the phase of an external clock The PLL phase-locked loop has three components:Phase detector PD, loop filter lf and voltage controlled oscillator VCO Principle: The external input reference signal is used to control the frequency and phase of the internal oscillation signal in the loop.PD, which detects the phase difference between the input signal

clock cycle: The clock cycle, also known as the oscillation period, is defined as the reciprocal of the clock pulse (it can be understood that the clock cycle is the inverse of the monolithic microcomputer external crystal oscillator, such as the crystal oscillator 12M, its time period is 1/12 us), is the most basic, the smallest unit of time in the computer. In a clock cycle, the CPU only completes one of

shift (the time point of the micro-frequency offset ). The maximum sample set time allowed in this algorithm is determined by the difference between the local frequency and the frequency of the received data, that is, during this time, the frequency difference is not enough to reverse the PRN code multiple times (related to the demodulation method, or it may not be enough to reverse the Carrier Multiple times ). Considering this restriction, the performance of many crystal

purposes. In this case, we need to find another method.When I used to write a single-chip microcomputer program in assembly language, this problem was relatively easy to solve. For example, if we use a 12 MHz crystal oscillator 51 with a delay of 20 us, we can use the following code to meet the general needs:MoV r0, #09 hLoop: djnz r0, loopThe instruction period of 51 single-chip microcomputer is 1/12 of the crystal

bitEX1 (IE.2) Enable exterior 1 external interrupt 1 interrupt allow bit ET0 (IE.1) Enable timer 0 T0 interrupt allow bitEX0 (ie.0) enable exterior 0 external interrupt 0 interrupt allow bit IP (b8h) Interrupt priority Interrupt Precedence register PS (IP.4) Priority serial port precedence flag bitPT1 (IP.3) Priority timer 1 Timer 1 precedence flag bitPX1 (IP.2) Priority exterior 1 external interrupt 1 precedence flag bit PT0 (IP.1) Priority timer 0 Timer 0 precedence flag bitPX0 (ip.0) Priorit

1.Q: What is the system clock. What is a clock system. A: Usually referred to as the system clock refers to the clock system, which is the oscillator (signal source), timing wake-up, frequency divider and other components of the circuit. The commonly used signal sources are crystal oscillators and RC oscillators. 2.Q: What is the function of the clock system? A: The clock is the pulse of the embedded system, the processor core in the clock driver t

The serial 51 in ATMEL has the same functions as 89C51. Command compatibility. The hex program does not require any conversion.Directly. Listen 51 only adds a watchdog function than 89C51. For other functions of iis51, refer to 89C51..The use of the watchdog is as follows:In program initialization, first write 01eh to the watchdog register (wdtrst address is 0a6h) and then 0e1h. ExcitingActive guard.Org 1, 0000Ljmp beginBegin:MoV 0a6h, # 01eh; send 1E firstMoV 0a6h, # 0e1h; then E1To activate th

defined (rvmdk) | defined (_ armcc_version) // In the Keil MDK Environment_ ASM voidSysctldelay (unsigned long ulcount){Subs r0, #1;BNE sysctldelay;Bx lr;}# Endif# If defined (CCS) // CCSVolatile unsigned long g_ulinlineccsworkaround;VoidSysctldelay (unsigned long ulcount){_ ASM ("delay? : Subs r0, #1 \ n""BnE. N delay? \ N""Bx LR \ n "); //// This is needed to keep Ti compiler from optimizing away this code.//G_ulinlineccsworkaround + = ulcount;}# Endif Sysctldelay () executes three Assembly s

been used for the oscilloscope, no error. As we are currently working on the arm9-system, we have already lowered these questions. If you have any research on it, please tell your younger brother to solve this problem, you can use it as a USB programmer! This line is directly inserted into the physical serial port and is still available.4. after making such a simple programmer, you can start to learn the AVR or 8051 microcontroller. After you are familiar with it, you can create a USB interface

DC-DC converter supports a wide range of power supply voltages: Vbat wide voltage mode: 2.1 to 3.6 V Pre-regulated 1.85 V mode Advanced Low Power mode Supports real-time clock (RTC) sleep: 4μa Low power deep sleep (lpps): 120 μA RX traffic (MCU activation): 59 [email protected] orthogonal frequency division multiplexing (OFDM) TX traffic (MCU activation): 229 [email protected], maximum power Idle connection (MCU in lpdms): 695 μA @ dtim = 1

concepts. One physical concept we all know is "electromagnetic spectrum ". This is the carrier of electromagnetic waves. It is produced by a relatively simple electronic device "oscillator. The oscillator emits a sine wave (remember this is the content of the high school ry class ?), Then we can adjust the oscillator to generate an electromagnetic wave with a sp