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Hi there fellow MSP430 programmers! I'm new at this so maybe you can help.

I'm running into trouble configuring the MSP430FR4133 PxSEL registers. In the MSP430FR4xx Family User's Guide, it is stated that the pin function select is controlled by TWO 8-bit registers, PxSEL0 and PxSEL1, to control primary/secondary/tertiary functions:

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The problem is: I can only find and access PxSEL0 on all ports, and PxSEL1 seems to be totally absent in both the msp430fr4133.h header definitions as well as in CCS's register browser:

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I'm confused as to why the FR4133 version of the device doesn't show the PxSEL1 registers in both the main header definitions or the register browser.

This poses a problem if I wish to configure pin 5.1 for the UCB0SCL function, because I can only set one bit in P5SEL0 and the other bit in P5SEL1 is ... either nowhere to be found, or I've got a case of the misunderstandings.

Any clue as to what is going on? Thanks!

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As you can see in the Input/Output Schematics section (6.9.13) of the datasheet, this chip has no pins that actually have a secondary or tertiary module function. Therefore, the PxSEL1 bit would always be zero, so TI did not bother to define its register symbol.

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  • \$\begingroup\$ Thanks! I was confused because at first glance, the pinouts of the device in the datasheet are shown as ( for example, P1.0 ) P1.0/UCA0TXD/UCA0SIMO/A0/Veref- This made me think that all these functions were accessible through setting P1SEL0 and P1SEL1 ... however, referencing the Port 1 Pin Functions chart in the datasheet shows me other registers are required to be modified to access some alternate pin functions. \$\endgroup\$
    – smoothVTer
    Jul 1, 2015 at 19:16

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