[UJA1169A] issue on RXD functionality and tblank parameter

[DaveZhu]

Hi, I'm now evaluating the data sheet of UJA1169A for our new product.

Since RXD pin is used as received CAN bit stream and interrupt output as well, how can I properly handle it (switch between 2 sets of software routines) when the RXD functionality changes? What should I do to avoid, like mis-interpreting interrupt as a CAN received bit '0'? And what is tblank parameter? There's no detailed explanation.

[JozefKozon]

Hi Dave,

the RXD pin is actually an bit stream output. 

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In both cases, as the bit stream or as an interrupt, the RXD pin is an output. Please refer to the Table 4. in the UJA1169A datasheet for RXD pin behavior.  

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With Best Regards,

Jozef

[DaveZhu]

Hi Jozef,

What I am wondering is what I should do during that small period right before/after the functionality of RXD is switched caused by internal circuit.

I'm afraid I'll miss interrupt or misinterpret RXD level.

[JozefKozon]

Hi Dave,

during the in between the UJA1169A states you cannot take the RXD pin state a valid anyway. You need to wait the specific time till the UJA1169A is in the required state, only then you can take the RXD pin state as valid, corresponding to the Table 4. 

Please refer to the Table 54. in the UJA1169A datasheet for the timings. 

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With Best Regards,

Jozef