SLAU144K December 2004 – August 2022 MSP430AFE221 , MSP430AFE222 , MSP430AFE223 , MSP430AFE231 , MSP430AFE232 , MSP430AFE233 , MSP430AFE251 , MSP430AFE252 , MSP430AFE253 , MSP430F2001 , MSP430F2002 , MSP430F2003 , MSP430F2011 , MSP430F2012 , MSP430F2013 , MSP430F2101 , MSP430F2111 , MSP430F2112 , MSP430F2121 , MSP430F2122 , MSP430F2131 , MSP430F2132 , MSP430F2132-EP , MSP430F2232 , MSP430F2234 , MSP430F2252 , MSP430F2252-Q1 , MSP430F2254 , MSP430F2272 , MSP430F2272-Q1 , MSP430F2274 , MSP430F2274-EP , MSP430F233 , MSP430F2330 , MSP430F235 , MSP430F2350 , MSP430F2370 , MSP430F2410 , MSP430F2416 , MSP430F2417 , MSP430F2418 , MSP430F2419 , MSP430F247 , MSP430F2471 , MSP430F248 , MSP430F2481 , MSP430F249 , MSP430F2491 , MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619 , MSP430G2001 , MSP430G2101 , MSP430G2102 , MSP430G2111 , MSP430G2112 , MSP430G2121 , MSP430G2131 , MSP430G2132 , MSP430G2152 , MSP430G2153 , MSP430G2201 , MSP430G2201-Q1 , MSP430G2202 , MSP430G2203 , MSP430G2210 , MSP430G2211 , MSP430G2212 , MSP430G2213 , MSP430G2221 , MSP430G2230 , MSP430G2231 , MSP430G2231-Q1 , MSP430G2232 , MSP430G2233 , MSP430G2252 , MSP430G2253 , MSP430G2302 , MSP430G2303 , MSP430G2312 , MSP430G2313 , MSP430G2332 , MSP430G2333 , MSP430G2352 , MSP430G2353 , MSP430G2402 , MSP430G2403 , MSP430G2412 , MSP430G2413 , MSP430G2432 , MSP430G2433 , MSP430G2444 , MSP430G2452 , MSP430G2453 , MSP430G2513 , MSP430G2533 , MSP430G2544 , MSP430G2553 , MSP430G2744 , MSP430G2755 , MSP430G2855 , MSP430G2955 , MSP430TCH5E
Port pins are often multiplexed with other peripheral module functions. See the device-specific data sheet to determine pin functions. Each PxSEL and PxSEL2 bit is used to select the pin function - I/O port or peripheral module function.
PxSEL2 | PxSEL | Pin Function |
---|---|---|
0 | 0 | I/O function is selected. |
0 | 1 | Primary peripheral module function is selected. |
1 | 0 | Reserved. See device-specific data sheet. |
1 | 1 | Secondary peripheral module function is selected. |
Setting PxSELx = 1 does not automatically set the pin direction. Other peripheral module functions may require the PxDIR bits to be configured according to the direction needed for the module function. See the pin schematics in the device-specific data sheet.
Setting PxREN = 1 When PxSEL = 1
On some I/O ports on the MSP430F261x and MSP430F2416/7/8/9, enabling the pullup/pulldown resistor (PxREN = 1) while the module function is selected (PxSEL = 1) does not disable the logic output driver. This combination is not recommended and may result in unwanted current flow through the internal resistor. See the device-specific data sheet pin schematics for more information.
;Output ACLK on P2.0 on MSP430F21x1
BIS.B #01h,&P2SEL ; Select ACLK function for pin
BIS.B #01h,&P2DIR ; Set direction to output *Required*
P1 and P2 Interrupts Are Disabled When PxSEL = 1
When any P1SELx or P2SELx bit is set, the corresponding pin's interrupt function is disabled. Therefore, signals on these pins will not generate P1 or P2 interrupts, regardless of the state of the corresponding P1IE or P2IE bit.
When a port pin is selected as an input to a peripheral, the input signal to the peripheral is a latched representation of the signal at the device pin. While PxSELx = 1, the internal input signal follows the signal at the pin. However, if the PxSELx = 0, the input to the peripheral maintains the value of the input signal at the device pin before the PxSELx bit was reset.