GPIO口设置方法

0 Preface/Foreword

参考博客：RISC-V E300 SOC架构介绍——5.电源常开域（Always on Domain）-CSDN博客

AON：Always ON domain，电源常开域

0.1 IO 外设初始化流程?

IO外设初始化流程包括：

1. Configure PAD, i.e., status of pins
2. Configure PINMUX, i.e., pin multiplex
3. Enable clock signal of peripheral
4. Determine initialization parameters of peripherals
5. Configure & Enable interrupt if necessary
6. Enable peripheral?

1 数据结构

2 软件分析

2.1 Pad_Config

/**
? * @brief ?config the corresponding pad.
? * @param ?Pin_Num: pin number.
? * ? ? This parameter is from ADC_0 to P4_1, please refer to rtl876x.h "Pin_Number" part.
? * @param ?AON_PAD_MODE: use software mode or pinmux mode.
? * ? ? This parameter can be one of the following values:
? * ? ? @arg PAD_SW_MODE: use software mode.
? * ? ? @arg PAD_PINMUX_MODE: use pinmux mode.
? * @param ?AON_PAD_PwrOn: config power of pad.
? * ? ? This parameter can be one of the following values:
? * ? ? @arg PAD_NOT_PWRON: shutdown power of pad.
? * ? ? @arg PAD_IS_PWRON: enable power of pad.
? * @param ?AON_PAD_Pull: config pad pull mode.
? * ? ? This parameter can be one of the following values:
? * ? ? @arg PAD_PULL_NONE: no pull.
? * ? ? @arg PAD_PULL_UP: pull this pin up.
? * ? ? @arg PAD_PULL_DOWN: pull thi pin down.
? * @param ?AON_PAD_E: config pad out put function.
? * ? ? This parameter can be one of the following values:
? * ? ? @arg PAD_OUT_DISABLE: disable pin output.
? * ? ? @arg PAD_OUT_ENABLE: enable pad output.
? * @param ?AON_PAD_O: config pin output level.
? * ? ? This parameter can be one of the following values:
? * ? ? @arg PAD_OUT_LOW: pad output low.
? * ? ? @arg PAD_OUT_HIGH: pad output high.
? * @retval None
? */

void Pad_Config(uint8_t Pin_Num,
? ? ? ? ? ? ? ? PAD_Mode AON_PAD_Mode,
? ? ? ? ? ? ? ? PAD_PWR_Mode AON_PAD_PwrOn,
? ? ? ? ? ? ? ? PAD_Pull_Mode AON_PAD_Pull,
? ? ? ? ? ? ? ? PAD_OUTPUT_ENABLE_Mode AON_PAD_E,
? ? ? ? ? ? ? ? PAD_OUTPUT_VAL AON_PAD_O)
{
? ? uint8_t tmpVal;
? ? uint8_t addr = PINADDR_TABLE[Pin_Num];

? ? tmpVal = btaon_fast_read_safe(addr);
? ? /* Clear reg value first */
? ? tmpVal &= ~0xF;
? ? /* Pull Config */
? ? if (AON_PAD_Pull == PAD_PULL_UP)
? ? {
? ? ? ? tmpVal |= Pull_En;
? ? }
? ? else if (AON_PAD_Pull == PAD_PULL_DOWN)
? ? {
? ? ? ? tmpVal |= (Pull_En | Pull_Direction);
? ? }
? ? /* Output Config */
? ? tmpVal |= (AON_PAD_O | (AON_PAD_E << 1));
? ? /* Write reg */
? ? btaon_fast_write_safe(addr, tmpVal);

? ? tmpVal = btaon_fast_read_safe(addr + 1);
? ? /* Pad control mode */
? ? if (AON_PAD_PwrOn)
? ? {
? ? ? ? tmpVal |= SHDN;
? ? }
? ? else
? ? {
? ? ? ? tmpVal &= ~SHDN;
? ? }
? ? if (AON_PAD_Mode)
? ? {
? ? ? ? tmpVal |= Pin_Mode;
? ? }
? ? else
? ? {
? ? ? ? tmpVal &= ~Pin_Mode;
? ? }
? ? /* Pad Power on mode */
? ? btaon_fast_write_safe((addr + 1), tmpVal);
}

2.2 Pinmux_Config?

?

/**
? * @brief ?Config pin to its corresponding IO function.
? * @param ?Pin_Num: pin number.
? * ? ? This parameter is from ADC_0 to P4_1, please refer to rtl876x.h "Pin_Number" part.
? * @param ?Pin_Func: mean one IO function, please refer to rtl876x_pinmux.h "Pin_Function_Number" part.
? * @retval None
? */
void Pinmux_Config(uint8_t Pin_Num, uint8_t Pin_Func)
{
? ? uint8_t pinmux_reg_num;
? ? uint8_t reg_offset;

? ? pinmux_reg_num = Pin_Num >> 2;
? ? reg_offset = (Pin_Num & 0x03) << 3;

? ? PINMUX->CFG[pinmux_reg_num] = (PINMUX->CFG[pinmux_reg_num] & ~(0xFF << reg_offset))
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? | Pin_Func << reg_offset;

? ? return;
}