Nios II定制指令用戶指南：With the Altera Nios II embedded processor, you as the system designer can accelerate time-critical software algorithms by adding custom instructions to the Nios II processor instruction set. Using custom
instructions, you can reduce a complex sequence of standard instructions to a single instruction implemented in hardware. You can use this feature for a variety of applications, for example, to optimize software inner
loops for digital signal processing (DSP), packet header processing, and computation-intensive applications. The Nios II configuration wizard,part of the Quartus® II software’s SOPC Builder, provides a graphical user interface (GUI) used to add up to 256 custom instructions to the Nios II processor.
The custom instruction logic connects directly to the Nios II arithmetic logic unit (ALU) as shown in Figure 1–1.
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
Frequently, voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low voltageelectronic reference.
隨機性發生器、冒泡分類和混洗一組12張牌的演示程序。
Demonstrates the use of a randomizer, bubble-sort and an array to "shuffle" a deck of 12 cards. I put it here for those of you who are trying to Figure out how to shuffle with a randomizer without having the same card appear two-or-more times.
CBC下寫的串口編程，API函數實例
I wish this site had been around when I was trying to Figure out how to make serial communications work in Windows95. I, like many programmers, was hit with the double-whammy of having to learn Windows programming and Win95 serial comm programming at the same time. I found both tasks confusing at best. It was particularly frustrating because I had, over the years, written so much stuff (including lots of serial comm software) for the DOS environment and numerous embedded applications. Interrupt driven serial comm, DMA transfer serial comm, TSR serial comm, C, assembler, various processors... you name it, it had written it. Yet, everything I knew seemed upside-down in the message-driven-callback world of Windows.
四套Latex模版，分別是：
A good model for writing Curriculum Vitae；
An excellent package to design slides using LaTeX；
A strong package to make floating Figure and table style；
For writing formal letters。
