MPC5xxx中的主题 Re: Send 32-bit SPI

Send 32-bit SPI

CHAOWeiXu — Fri, 29 Apr 2022 11:39:19 GMT

hi，

I use the MPC5744P SPI module.It uses 16 bit SPI to send, but I want it to send 32 bits.I try to manually control the CS to send 32 bits.But the SCK signal will be delayed when it is sent. I want to send two 16 bits in a row.

Thanks

Re: Send 32-bit SPI

PetrS — Tue, 03 May 2022 08:02:32 GMT

Hi,

what code do you use for this? Some delay can be caused by SW delay, also by HW (see CTAR setting).
Manual control of CS is not needed, module is able to do that, if need CS low between words use continuous selection format, check chapter 49.4.4.5 Continuous Selection Format of the RM.

BR, Petr

Re: Send 32-bit SPI

CHAOWeiXu — Tue, 03 May 2022 15:07:49 GMT

hi,Mr,Petr

I use Simulink to build the model. Its name is NXP_ MBDToolbox_ MPC57xx.

I want the master to send 32-bit data to the slave, but it only supports sending 16-bit data.

When I adjust the transfer size to 32, the oscilloscope displays abnormal.When I adjust the transfer size to 16, if I send 16 bits twice in a row, there will be a delay between SCKs.In the attachment are my model and the oscilloscope image when it is sent twice in a row.

Thanks，

Re: Send 32-bit SPI

PetrS — Wed, 04 May 2022 10:07:43 GMT

Hi,

if using MATLAB/Simulink with toolbox please ask question directly on its Community space;
https://community.nxp.com/t5/Model-Based-Design-Toolbox-MBDT/bd-p/mbdt

BR, Petr

Re: Send 32-bit SPI

CHAOWeiXu — Wed, 04 May 2022 12:24:11 GMT

Thank you for your help.