IIS2dh多字节读取不起作用？

你好ST社区，
我有一个使用IIS2DH MEMS加速度计的应用程序。我遇到了一些问题，所以要进行故障排除，我买了STEVAL-MKI168V1子板和SEVAL-MKI109V2主板。使用这些套件，并使用STSW-MKI109W软件包，我能够解决我的大部分问题。
我还有一个问题。多字节读取在4线SPI模式下不起作用。这是一些细节。
1.命令字节中的/ MS位设置为1。
2.我的命令序列似乎与示例代码的spi_mems.c中的SPI_Read_MultiData没有什么不同。
3.当读出寄存器（0x20至0x3F）时，如果我使用单字节读取模式读取每个寄存器，则会得到正确的数据。如果我使用多字节读取模式，我将获得没有意义的数据。例如，我可能会读取INT1_SRC（0x31）并在最高有效位（假设为零）中得到1。
在查看示例代码和使用Unico应用程序时，我注意到了一些事情。
1.我使用IIS2DH运行Unico应用程序，并使用逻辑分析器监视总线。即使我单击“寄存器”选项卡中的“全部读取”按钮，它似乎也不会执行多字节读取。相反，它使用单字节模式读取每个寄存器。
2.我在固件中搜索，发现有2个文件文件被调用
SPI_Read_MultiData，但也有2个文件被注释掉，有利于单字节读取。我很难找到确定IIS2DH的示例代码是否会使用多字节读取的方法。据我所知，看起来我可能正在使用lis2dh12.c，它已经注释掉了SPI_Read_MultiData。
奇怪的是，在示例代码的某些文件中禁用了多字节读取。 IIS2DH是否有一个我不知道的勘误表？多字节读取是IIS2DH的已知问题吗？
谢谢
杰夫



以下为原文




Hello ST Community,
I have an application using the IIS2DH MEMS accelerometer. I was running into some issues, so to troubleshoot, I bought the STEVAL-MKI168V1 daughter board and SEVAL-MKI109V2 mother board. Using these kits, and by using the STSW-MKI109W software package, I was able to troubleshoot the majority of my issues.
I have one issue that remains. The multibyte read does not work in 4 wire SPI mode. Here are some details.
1. I have the /MS bit in the command byte set to 1.
2. My command sequence appears to be no different than SPI_Read_MultiData in spi_mems.c of the sample code.
3. When reading out the registers (0x20 to 0x3F), I get correct data if I read each register using the single-byte read mode. If I use the multi-byte read mode, I will get data that doesn't make sense. For example, I might read INT1_SRC (0x31) and get a 1 in the most significant bit (supposed to be zero).
I noticed a few things while looking at the sample code and using the Unico application.
1. I ran the the Unico application with the IIS2DH and used a logic analyzer to spy the bus. It never seems to perform a multi-byte read, even when I click the 'Read All' button in the Registers tab. Instead, it reads each register using the single-byte mode.
2. I did a search in the firmware and found that 2 files files called
SPI_Read_MultiData, but there are also 2 files where it is commented out in favor of the single-byte read. I'm having a hard time finding my way around to confirm whether the sample code for the IIS2DH would use multi-byte reads or not. As far as I can tell, it looks like I might be using lis2dh12.c, which has SPI_Read_MultiData commented out.
It is curious that multi-byte read is disabled in some files of the sample code. Is there an errata for the IIS2DH somewhere that I'm not aware of? Is multi-byte read a known problem for the IIS2DH?
Thanks
Jeff