CCS/TMS570LS0914: Some of the code generated by HAL is not understood

jian yin

Part Number: TMS570LS0914

Tool/software: Code Composer Studio

I wanted to understand the composition of the code, but I didn't quite understand the parts.

For example, the MSK part of the code,”0x00000333U“ is what I set at HAL's messagebox，"0x0000007FF"because I set the standard CAN.

But what I don't understand is the meaning of 0xC0000000U and shift left 18.

I hope your answers can solve my doubts.Thank you. I wish you all a happy Halloween.

over 7 years ago

0 Chester Gillon over 7 years ago

Guru 92251 points

tsukiko said:
But what I don't understand is the meaning of 0xC0000000U and shift left 18.

I agree that from the posted HAL generated code there are no comments explaining the "magic numbers". From looking at the TMS570LS09x/07x 16/32-Bit RISC Flash Microcontroller Technical Reference Manual (Rev. A) :

1. From Table 24-22. IF1/IF2 Mask Register Field Descriptions the value 0xC0000000U means the Mask Extended Identifier (MXtd) and Mask Message Direction (MDir) bits are set.

2. From Table 24-2. Message Object Field Descriptions the 11-bit ("standard") identifier bits are stored in ID[28:18] bits, which explains the shift left 18.

0 jian yin over 7 years ago in reply to Chester Gillon

Prodigy 180 points

Thank you for your generous help，I wish you all a happy Halloween!

0 Miro over 7 years ago in reply to jian yin

TI__Mastermind 21425 points

Thanks Chester!

Regards,
Miro

0 jian yin over 7 years ago in reply to Chester Gillon

Prodigy 180 points

I'm sorry, I have a new question, like the IF1MSK part above, why does it have to be written in 3 paragraphs

0 Miro over 7 years ago in reply to jian yin

TI__Mastermind 21425 points

Hello tsukiko,
Did you mean: canREG1->IF1MSK = 0xC0000000U | (uint32)((uint32)((uint32)0x00000333U & (uint32)0x000007FFU) << (uint32)18U); ?
You can set it as one digit, but it will be harder to follow what was set and to correct when needed.

Best regards,
Miro

0 jian yin over 7 years ago in reply to Miro

Prodigy 180 points

Thanks!

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CCS/TMS570LS0914: Some of the code generated by HAL is not understood