XAPP391错误检测

你好。
我试图了解Xilinx参考设计（XAPP391：使用CoolRunner-II CPLD设计16b / 20b编码器/解码器））。
当执行功能模拟（包括在下载文件中）时，解码器的错误检测信号在解码10位字0x1C7,0x1BE，0x13E，0x0BE和0x2BE时变为有效。
设计提供的测试平台连接编码器和解码器，因此只有合法的10位字进入解码器。
8bit  - > enc  - > 10bit  - > dec  - > 8bit
我认为测试平台没有错误注入。
在错误情况下，解码器呈现的8位字是可以的。
那么为什么会出现这些错误呢？
有人已经使用过该参考设计并遇到了模拟或实际硬件实现方面的困难吗？
RGDS
安德烈



以下为原文

Hi.
I am trying to understand the Xilinx reference design (XAPP391:
Design
of a 16b/20b Encoder/Decoder Using a CoolRunner-II CPLD)).
When performing the functional simulation (which is included in the
download files) the error detection signal of the decoder becomes
active
on decoding of 10bit words 0x1C7, 0x1BE, 0x13E, 0x0BE
and 0x2BE.

The testbench provided with the design connects the encoder
and the decoder, so that only legal 10bit words get into the decoder.
8bit --> enc --> 10bit --> dec --> 8bit

I think that there is no error injection in the testbench. In the
error cases
the 8bit words presented by the decoder are OK.

So why does these errors occur ? Has someone
already used that reference design and has met
difficulties in simulation or real hardware implementation ?

Rgds
Andre