怎么从pic16F1459升级到pic18F25K50

这两个家庭每指令需要4个时钟周期。PIC16家族有14位指令，PIC18有16位指令，这意味着GOTO指令可以进一步到达，而且更少的页面交换来访问RAM和SFRs。影响你的两种不同。



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    Both families require 4 clock cycles per instruction.
The PIC16 family has 14 bit instructions, and the PIC18 has 16 bit instructions, which means GOTO instructions can reach further, and there's less page swapping to access RAM and SFRs.
You really need to study the peripherals to see if there are any differences that affect you.
 

谢谢指教！



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    thanks for advice!

PIC16F1459和PIC18F25K50都可以运行在48 MHz max＝12 MIPS指令＝83 ns。IMHO，除非您需要更多的内存或硬件乘法，PIC18FXXK50不如PIC16F145X。您还可以切换到PIC24FJ——有很多模型，它们可以运行在16 MIPS，这实际上是很多F。ASTER比PIC16／18，因为它们有更好的指令集。



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    Both PIC16F1459 and PIC18F25K50 can run at 48MHz max = 12 MIPS = 83 ns per instruction.
 
IMHO, unless you need more memory or hardware multiplication, PIC18FxxK50 is inferior to PIC16F145x.
 
You can also switch to PIC24FJ - there are plenty of models and they can run at 16 MIPS, which is actually much faster than PIC16/18 because they have much better instruction set.
 

谢谢NothGee，提供有用的信息；事实上，我一直在想为什么PIC18FXXK50有更多的功能和更强大的功能，但是价格大约是没有K的PIC18FXX50的一半；我想知道它们之间的区别……像PIC18F2550和PIC18F25K50。如果有一个，我会检查PIC24FJ。想要……



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    Thank you NorthGuy, for useful information;
in fact i have been wondering why  PIC18FxxK50 is of more functions and more powerful,but price is about half of that PIC18Fxx50 without K;
I wand to know the difference between them......like pic18F2550 and pic18F25K50.
 
I will check PIC24FJ ,if there is one i want......

“K”系列是较新的，在硅中使用改进的工艺，因此成本更低。您将找到一个合适的/更好的PIC24，YEP，它们不会是PIN兼容的（并且可能不会EEPROM）。



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    "K" series is newer, use improved processes in silicon, and hence comes to cost less.
 
You will find a suitable/better PIC24, yep, they just won't be pin compatible (and possibly will have no EEprom)

这意味着没有K的产品将被K系列取代，因为改进的过程，低成本，更强大。



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    does that mean product without K will be replaced by K series due to improved process,low cost,and more powerful.

并非总是如此。Microchip从未放弃或改变现有设备。许多芯片有更好的替代品介绍，但这将取决于它们有多受欢迎。



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    Not always.
Microchip never drop or change existing devices.
Many chips have better replacements introduced, but it would depend how popular they were.
 

PIC18F25K50有一个5位DAC，它的USB可以在没有外部OSC的情况下工作。电压频率也不同。还要检查Errasas…如果你想用MLA（应用程序的微芯片库）运行一些演示，新版本的MLA可能不会覆盖旧的PICS。



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    PIC18F25K50 has a 5bit DAC and its USB can work without external OSC.
 
The Electrical Spec is also a little different.  The Voltage-Frequency is also different.  Also check the erratas... 
 
If you want to run some demos with the MLA(Microchip Libraries for Applications), the newer versions of MLA might not cover old PICs.

你也必须考虑支持组件。唯一的USB PICS，可以直接从USB VBUS运行没有一个调节器，是8位PIC16F145X，PIC18FX45 X和“FX55 X，和PIC18FXXK50家庭。没有USB的5V PIC24/DSPIC部件，并且没有5V PIC32部件，并且作为未来的产品，具有16和32位内核似乎仅是3.3V（或更低），我怀疑将永远改变非K PIC18部件，PIC18F1XK50部件需要晶体，所以对于最小成本/部件计数设计。n您限于PIC16F145X，或28引脚或高PIC18FXXK50。



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    You also have to consider the support components required.
The ONLY USB PICs that can operate direct from USB Vbus without a regulator, are the 8 bit  PIC16F145x, PIC18Fx45x and 'Fx55x, and the PIC18FxxK50 families.   There are no 5V PIC24/dsPIC parts with USB and no 5V PIC32 parts at all, and as future products with  16 and 32 bit cores seem to be exclusively 3.3V (or lower), I doubt that will ever change   The non-K PIC18 parts and the PIC18F1xK50 parts need a crystal, so for a minimum cost/component count design you are limited to PIC16F145x,  or a 28 pin or higher PIC18FxxK50.

较旧的图片成本更高，因为它们是旧的（并且不再是批量生产）。更新的图片总是花费更少。但是更新的图片通常更好。因此，没有理由使用过时的图片来进行新的设计。



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    Older PICs cost more because they're old (and are not mass produced any more I guess). Newer PICs always cost less. But newer PICs are usually better. So, there's no reason to use obsolete PICs for new designs.

我怀疑这种定价在很大程度上是一种蓄意限制旧芯片需求的政策。这样，当晶片生产线关闭时，您不必浪费时间和资源调整芯片设计来运行在另一行或堆堆上，从而满足剩余需求。说服客户他们并不真的想要老芯片比微芯片的信誉要好得多，比如经常上一次发布他们的竞争对手的购买通知。我同意其余的用于批量生产，但是对于低数量或一次性的产品来说，能够节省STA的开发节约。RT从一个成熟的，经过测试的固件，一个旧的芯片，你已经知道像你的手可能远比节省到一个新的更便宜的芯片，你不知道/这很可能解释了普及的PIC18FX550芯片爱好者的USB项目S.



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    I suspect the pricing is to a large extent a deliberate policy to limit demand for older chips.  That way when a wafer production line shuts down, you don't have to waste time and resources tuning the chip designs to run on another line or stock-pile so many dies to satisfy remaining demand.   Persuading customers they don't really want old chips is far better for Microchip's reputation than frequently issuing last time buy notices like their competitors.
 
I'd agree with the rest of that for volume production, but for low quantities or one-offs, the development savings of being able to start from mature, well tested firmware for an older chip that you already know like the back of your hand are likely to be far far greater than the savings from changing to a newer cheaper chip you don't know well/  This probably explains the popularity of the PIC18Fx550 chips for hobbyist USB projects.

较新的更小几何尺寸的芯片每晶片获得更多的芯片。旧的更大，体积也在下降。正如我所听到的，旧的芯片是用晶圆制造的，晶圆是储存的，直到需要。因此存在存储成本。建立一个短时间跑的休息时间。从有利的方面来看，仍然有人出售他们20年的16CXX设计。



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Newer Chips with Smaller Geometry get more chips per Wafer.  Older ones are Bigger and their volumes drop.
As I heard the Older chips are made in wafers and the Wafers are stored until needed. So there is storage costs. And set up an break down time for the shorter runs.
On the Plus side there are people still selling their 20 year 16CXX designs.

人们不为这些芯片做新的设计。他们只是使用现成的设计（通常是在HEX文件级），所以他们需要精确的模型，没有选择。我不相信旧的芯片有任何好处，如果你设计新的东西。



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People don't do new designs for these chips. They just use ready-made designs (often on the HEX file level), so they need the exact model and do not have a choice.
 
I don't believe that older chips have any benefits if you design something new.