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Why is there no DDR (data direction register) for PORTA on RCM4300?

+1 vote
asked Apr 17, 2018 in Rabbit by rjames New to the Community (1 point)
recategorized Apr 17, 2018 by LeonidM

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1 Answer

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Port A is also used as the "slave port". Bits 2-4 of SPCR control whether it's all input, all output, a slave port or used for auxiliary I/O (an 8-bit data bus with a portion of port B used as address lines and a pin on port E used as a chip select).
answered Apr 17, 2018 by TomCollins Veteran of the Digi Community (1,453 points)
Thanks Tom.  I do not find the digi documentation straight forward at all.  It took me 2 days to find the SPCR reference.  The 4300 documentation Section 5.2.1 Digital I/O is a couple of paragraphs with no mention of the 4000 uP documentation; very frustrating.
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