RT1052 LPSPI Half duplex transfers supporting 2-bit transmit or receive on each clock edge

[wang3_wang]

我在使用RT1052做设计，我希望使用LPSPI主模式的半双工模式的 Half duplex transfers supporting 2-bit transmit or receive on each clock edge (masteronly)功能与外接的ADC通讯读取读取转换值。但不知道其数据SDI和SDO引脚如何配置？特别是SDO脚。NXP的MCUXpressoconfig tool也没找到相关设置项，头文件里只找到lpspi_transfer_width_t枚举定义，其库文件也没有找的引用和例子。Transmit Command (TCR)寄存器的WIDTH位也在库文件没有找到配置项。lpspi_pin_config_t配置应该如何选择？这是我的困惑，在网上也没有找到资料，向您请教一下

[wang3_wang]

是的，以外部ADC作为从机，只需要RT052作为主机读出数据其数据宽度为16位，只需要半双工的2位读取，提高数据吞吐率。在文档i.MX RT1050 Processor Reference Manual的47.4 Signal descriptions 表Table 47-12. Signals找到引脚描述，硬件已做了修改。但软件调试还是有问题，不能得到希望得到的ADC数据。另外NXP的iMCUXpresIsoconfig tool关于LPSPI的里设置波特率Baud rate和主机SCK输出频率如何换算，我的外设SCK频率最大为20M主机的Baud rate取值应该是多大？

[PabloAvalos]

Hi @wang3_wang 

Thanks a lot for your response.

So, basically you want to know how to convert the baud rate in LPSPI and the SCK output frequency of the host? and also, what is the Baud rate of the host (RT1050 in this case), with a maximum SCK frequency of 20MHz (for Slaves and Master among) ?

Please if you can reply on english, I would appreciate it, so I can understand it better.

Thank you.
Pablo Avalos.

[PabloAvalos]

Hi @wang3_wang 

Regarding your issues, I was assigned to handle your case.

I just want to confirm if this is what you are asking:

"I am using RT1052 for design, and I want to use the Half duplex transfers supporting 2-bit transmit or receive on each clock edge (masteronly) function of the half-duplex mode of the LPSPI master mode to communicate with the external ADC to read the conversion value. But I don't know how to configure its data SDI and SDO pins? Especially the SDO pin. NXP's MCUXpresso config tool did not find relevant setting items. Only the lsppi_transfer_width_t enumeration definition was found in the header file, and there were no references and examples found in its library files. The WIDTH bit of the Transmit Command (TCR) register also did not find configuration items in the library file. How should the lpspi_pin_config_t configuration be selected? This is my confusion, and I haven't found any information on the Internet. I would like to ask you for advice."

Also, I would like to know, which pins are those in the Reference Manual? "data SDI and SDO pins", I have never heard about those.

Please remember that our RT requests are too high these days and personal on holiday, so the answers might be delayed more than usual.

Have a nice new year's eve holiday.
Best Regards.
Pablo Avalos.