16位 MSP430FR2353 芯片P1.7引脚配置成VREF+输出2.5V 如何配置？

user5707170

Other Parts Discussed in Thread: MSP430FR2353

下面是我的配置

WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

PM5CTL0 &= ~LOCKLPM5;                     // Disable the GPIO power-on default high-impedance mode
                                            // to activate previously configured port settings
P1SEL0 |= BIT7;
P1SEL1 |= BIT7;
// Configure reference module
PMMCTL0_H = PMMPW_H;                                      // Unlock the PMM registers
PMMCTL2 = INTREFEN | REFVSEL_2 | EXTREFEN_1;              // Enable internal 2.5V reference

while(!(PMMCTL2 & REFGENRDY)); // Poll till internal reference settles

，但是测量时仅仅测量出来1.2V 我想输出2.5V 不知道怎么配置下能否提供下例程

5 年多前

0 Susan Yang 5 年多前

TI__Guru**** 252096 points

您现在是想配置为外部参考电压2.5V？

您可以参考数据手册

www.ti.com/.../msp430fr2353.pdf

The device contains three on-chip references:
• Internal shared reference (1.5 V, 2.0 V, or 2.5 V)
• 1.2 V for external reference (VREF pin)
• 1.2 V low-power reference for eCOMP

P1.7/UCA0TXD/UCA0SIMO/TB0.2/TDO/OA1+/A7/VREF+ can support a buffered external 1.2-V output when EXTREFEN = 1 in the PMMCTL2 register

0 user5707170 5 年多前回复 Susan Yang

Intellectual 580 points

我想直接通过这个引脚直接输出2.5V ，作为外部的参考电压

PMMCTL2 = INTREFEN | REFVSEL_2 | EXTREFEN_1; // Enable internal 2.5V reference 选择了2.5V 但是输出是2.5V也对这个寄存器操作了

下面的操作配置还是输出1.2V

WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

PM5CTL0 &= ~LOCKLPM5; // Disable the GPIO power-on default high-impedance mode
// to activate previously configured port settings
P1SEL0 |= BIT7;
P1SEL1 |= BIT7;
// Configure reference module
PMMCTL0_H = PMMPW_H; // Unlock the PMM registers
PMMCTL2 = INTREFEN | REFVSEL_2 | EXTREFEN; // Enable internal 2.5V reference

while(!(PMMCTL2 & REFGENRDY)); // Poll till internal reference settles

ADCMCTL0 = ADCINCH_7 | ADCSREF_0; // A1 ADC input select = OA0 output
// Vref = DVCC

如果配置ADC/DAC的内部参考电压是可以的，我仅仅是将1.7引脚配置输出2.5V是失败的，也通过ADC通道的选择

非常感谢你的回答