DMA向导禁止将8位SAR ADC链接到8位VDAC

DMA向导不允许将8位SAR ADC连接到8位VDAC。
它抱怨不兼容的突发大小。具体的错误是“所选的源和目的地具有不兼容的突发大小。不能选择有效的大小。
附上一个包含三个相关组件的最小示例项目。这足以重现错误信息。还附加了错误消息的截图。
我怀疑这是由于SAR ADC被永久地卡在16位寄存器配置中，从DMA的角度来看，即使该组件配置为8位分辨率。这意味着DMA配置假定最小的突发大小为2字节，即使1字节的突发大小应该是很好的。
在SAR ADC数据表的DMA部分中，我看到了关于AcdSARARWRK0YOPTR源的注释：“接收一个2字节的结果，用于转换，结果总是具有12位分辨率。”这支持先前怀疑DMA突发大小不能缩小以匹配配置的8位RES。洗脱。
DMA向导将分辨率从1到3字节缩放DeltasigMA ADC突发大小，因为分辨率从8位变为20位。DeltasigMA数据表还将这些突发大小列为依赖于分辨率的ADCJ-DESIGLDEXYSAMPYPTR的有效长度。我惊讶的是，SAR ADC不能同样地缩放突发宽度。
这是一个错误，还是仅仅是SAR ADC硬件的限制？
除了使用DeltasigMA ADC而不是SAR ADC之外，还有什么可行的建议吗？
我怀疑有可能把DMA源地址指向ADCYSARA WRK0YRG，它包含相关的8位值。
我认为一种选择是链接一对TDS，每个TD读取一个字节，其中第一个TD传递第一个字节到8位VDAC，而第二个TD只将另一个字节扔掉。
我还发现这两个未解决的线程遇到相同的突发宽度问题。
从SAR到VDAC的DMA
为什么我无法通过DMA将数据从ADCYSAR传输到VDAC8？
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SalaAdcdDMAYDAC.Cyrj.CaseVo.01.Zip
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     以下为原文
  The DMA Wizard does not allow linking an 8-bit SAR ADC to an 8-bit VDAC.
It complains about incompatible burst sizes. The specific error is "The selected Source and Destination have incompatible Burst sizes. No valid size can be selected".

A minimal example project just containing the three relevant components added to the schematic is attached. This is enough to reproduce the error message. Also attached a screenshot of the error message.

I suspect this is due to the SAR ADC being permanently stuck in a 16-bit register configuration from the DMA's perspective, even if the component is configured with 8-bit resolution. This means that the DMA configuration assumes a minimum burst size of 2 bytes, even though a burst size of 1 byte should be fine.

In the DMA section of the SAR ADC datasheet, I see this comment about the ADC_SAR_WRK0_PTR source: "Receive a 2-byte result for a conversion with a result that always has 12-bit resolution." This supports the previous suspicion that the DMA burst size cannot shrink to match the configured 8-bit resolution.

The DMA Wizard scales the DeltaSigma ADC burst size correctly from 1 to 3 bytes as the resolution changes from 8-bit to 20-bit. The DeltaSigma datasheet also lists these burst sizes as valid lengths of ADC_DelSig_DEC_SAMP_PTR depending on resolution. I'm just surprised that the SAR ADC cannot scale burst width similarly.

Is this a bug, or just a limitation of the SAR ADC hardware?
Are there any workaround suggestions besides just using the DeltaSigma ADC instead of the SAR ADC?
I doubt it's possible to just point the DMA source address to ADC_SAR_WRK0_REG, which contains the relevant 8-bit value.

I'm thinking one option is to chain a pair of TDs that each read one byte, where the first TD passes the first byte along to the 8-bit VDAC, and the second TD just throws the other byte away.

I also found these two unresolved threads which encountered the same burst width issue.
DMA from SAR to VDAC
Why I am unable to transfer data from ADC_SAR to VDAC8 Via DMA?

•    burst_size_error.png 182.8 K
•   SAR_ADC_DMA_DAC.cyprj.Archive01.zip 18.2 K