MIBSPI as slave - problems

Peter Schuetz

Prodigy 80 points

Other Parts Discussed in Thread: HALCOGEN

On an RM42 i want to use the MIBSPI1 as slave. Configured the SPI with HalCoGen. Using Keil compiler.

But then I write to the TX buffers, I cant see the written data completely, some parts are masked out to zero.

Also the arrangement of the bytes seems to be not OK.

Can there be a problem with the byte order, may be in the generated code?

over 12 years ago

0 Sunil Oak over 12 years ago

TI__Mastermind 49120 points

Peter,

How do you write the data to be transmitted? Do you use the mibspiSetData function generated by HALCoGen?

Regards, Sunil

0 Peter Schuetz over 12 years ago in reply to Sunil Oak

Prodigy 80 points

Yes, I used this function. And the bytes seemed to be in the false place.

Then I found out, that the definition for "little endian" in the reg_mibspi.h is not defined. So the byte order was wrong, and some parts of the data are not writeable. This seems to be an fault of HalCoGen for Keil.

After defining __LITTLE_ENDIAN__=1 in the compiler settings it works.

But the slave mode is not well defines in datasheet. What is the meaning of the CSNR field for slave mode? It seems to be the input pattern of all chip select lines.

Is there any document for using MibSPI as slave? Without DMA on the RM42 I have to use it.

Regards, Peter

0 Peter Schuetz over 12 years ago in reply to Peter Schuetz

Prodigy 80 points

Another question for MibSPI slave mode. Is there a chance to change the transfer group form 0 to another without changing signals on the CS pins?

Or what to do if I want to change the number of buffers while the program is runnig?

I want to work in 2 modes with different data packtes. So I have to change the length to get the ready signal on the right time.

Regards, Peter

0 Jean-Marc Mifsud over 12 years ago in reply to Peter Schuetz

TI__Mastermind 22375 points

Peter,

When MIBSPI is used in slave mode, the CS lines are used to decode which transfer group has to be used (on the slave)

Please have a look at the following threads:

http://e2e.ti.com/support/microcontrollers/hercules/f/312/p/261331/914621.aspx#914621

http://e2e.ti.com/support/microcontrollers/hercules/f/312/p/287056/1012758.aspx#1012758

Please let me know if this is helpful.

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MIBSPI as slave - problems