在Spartan 3E板上怎么解析GPS句子

您可能需要通过'解析'精确定义您的意思。
如果我正在解析NMEA字符串并且只想提取位置更新并忽略所有其他字符串，我会设计一个执行此操作的状态机：
等待UART中的角色
检查它是否是$。
如果没有，请等待行尾字符然后返回开始。
如果是，请等待下一个字符。
检查下一个字符是否为G.如果不是..
检查下一个字符是否为P.如果不是..
检查下一个字符是否为G.如果不是..
检查下一个字符是否为G.如果不是..
检查下一个字符是否为A.如果不是..
检查下一个字符是否为逗号。
如果没有..现在，你已经建立了它的GPGGA位置更新。
下一批字符将成为UTC时间戳的一部分。
读出时间戳直到下一个逗号，可能将其从ASCII转换为二进制数并将其存储在寄存器中。
等等
您使用分布式还是BRAM取决于您要存储多少数据（只有一条记录，或几百条？）以及您在设计中剩余的资源数量（您是否已将所有BRAM用于其他事项？）
请注意，使用PicoBlaze或MicroBlaze进行此类任务可能要容易得多。
GPS不是一个非常高速的设备（例如更新可能只有10赫兹），因此您可以通过使用处理器节省大量的开发时间。



以下为原文

You may need to define precisely what you mean by 'parse'.
 
If I were parsing NMEA strings and just wanted to extract, say, position updates and ignore all others, I would design a state machine that did this:
 

• Wait for a character from the UART
  
• Check if it's a $. If not, wait for end of line character and go back to start. If it is, wait for next character.
  
• Check if next character is a G. If not..
  
• Check if next character is a P. If not..
  
• Check if next character is a G. If not..
  
• Check if next character is a G. If not..
  
• Check if next character is a A. If not..
  
• Check if next character is a comma. If not.. Now, you've established it's a GPGGA position update. 
  
• The next lot of characters will be part of the UTC timestamp. Read out timestamp until the next comma, perhaps converting it from ASCII to a binary number and storing that in a register.
  
• etc.
  

Whether you use distributed or BRAM depends on how much data you want to store (just one record, or hundreds?) and how many resources you have left in your design (have you already used all of the BRAM for other things?)
 
Note that it may be considerably easier to use PicoBlaze or MicroBlaze for this sort of tasks. A GPS is not a very high speed device (e.g. updates may only be at 10 Hz) so you may save a lot of development time by using a processor.
 

“我找到了一个用于GPS解析的FSM”发布该代码或其链接将有所帮助，以及描述它似乎无法工作。从个人经验来看，用VHDL编写文本解析器很难。
写一个合成的东西确实非常难。
使用嵌入式处理器进行操作可能更容易，即使这意味着您必须学习如何使用EDK / XPS。
------------------------------------------“如果它不起作用
模拟，它不会在板上工作。“



以下为原文

"I have found an FSM for the GPS Parsing"

Posting that code or a link to it would help, as well as describing HOW it doesn't seem to work.

From personal experience, writing a text parser in VHDL is hard. Writing one that will synthesize could be really very hard indeed. Doing it with an embedded processor is probably easier, even if it means that you have to learn how to use EDK/XPS.
------------------------------------------
"If it don't work in simulation, it won't work on the board."