/*
*******************************************************************************
* Copyright (c) 2019, STMicroelectronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************
* Automatically generated from STM32F401R[(B-C)|(D-E)]Tx.xml
*/
#include "Arduino.h"
#include "PeripheralPins.h"
/* =====
* Note: Commented lines are alternative possibilities which are not used per default.
* If you change them, you will have to know what you do
* =====
*/
//*** ADC ***
#ifdef HAL_ADC_MODULE_ENABLED
WEAK const PinMap PinMap_ADC[] = {
{PA_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 0, 0)}, // ADC1_IN0
{PA_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 1, 0)}, // ADC1_IN1
{PA_2, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 2, 0)}, // ADC1_IN2
{PA_3, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 3, 0)}, // ADC1_IN3
{PA_4, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 4, 0)}, // ADC1_IN4
{PA_5, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 5, 0)}, // ADC1_IN5
{PA_6, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 6, 0)}, // ADC1_IN6
{PA_7, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 7, 0)}, // ADC1_IN7
{PB_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 8, 0)}, // ADC1_IN8
{PB_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 9, 0)}, // ADC1_IN9
{PC_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 10, 0)}, // ADC1_IN10
{PC_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 11, 0)}, // ADC1_IN11
{PC_2, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 12, 0)}, // ADC1_IN12
{PC_3, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 13, 0)}, // ADC1_IN13
{PC_4, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 14, 0)}, // ADC1_IN14
{PC_5, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 15, 0)}, // ADC1_IN15
{NC, NP, 0}
};
#endif
//*** No DAC ***
//*** I2C ***
#ifdef HAL_I2C_MODULE_ENABLED
WEAK const PinMap PinMap_I2C_SDA[] = {
{PB_3, I2C2, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF9_I2C2)},
{PB_4, I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF9_I2C3)},
{PB_7, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
{PB_9, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
{PC_9, I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C3)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_I2C_SCL[] = {
{PA_8, I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C3)},
{PB_6, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
{PB_8, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
{PB_10, I2C2, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C2)},
{NC, NP, 0}
};
#endif
//*** PWM ***
#ifdef HAL_TIM_MODULE_ENABLED
WEAK const PinMap PinMap_PWM[] = {
//{PA_0, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
{PA_0, TIM5, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 1, 0)}, // TIM5_CH1
//{PA_1, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 2, 0)}, // TIM2_CH2
{PA_1, TIM5, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 2, 0)}, // TIM5_CH2
//{PA_2, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 3, 0)}, // TIM2_CH3
{PA_2, TIM5, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 3, 0)}, // TIM5_CH3
//{PA_2, TIM9, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 1, 0)}, // TIM9_CH1
//{PA_3, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 4, 0)}, // TIM2_CH4
{PA_3, TIM5, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 4, 0)}, // TIM5_CH4
//{PA_3, TIM9, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 2, 0)}, // TIM9_CH2
{PA_5, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
{PA_6, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
//{PA_7, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 1)}, // TIM1_CH1N
{PA_7, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
{PA_8, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 0)}, // TIM1_CH1
{PA_9, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 0)}, // TIM1_CH2
{PA_10, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 0)}, // TIM1_CH3
{PA_11, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 4, 0)}, // TIM1_CH4
{PA_15, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
//{PB_0, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 1)}, // TIM1_CH2N
{PB_0, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 3, 0)}, // TIM3_CH3
//{PB_1, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 1)}, // TIM1_CH3N
{PB_1, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 4, 0)}, // TIM3_CH4
{PB_3, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 2, 0)}, // TIM2_CH2
{PB_4, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
{PB_5, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
{PB_6, TIM4, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 1, 0)}, // TIM4_CH1
{PB_7, TIM4, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 2, 0)}, // TIM4_CH2
{PB_8, TIM4, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 3, 0)}, // TIM4_CH3
//{PB_8, TIM10, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM10, 1, 0)}, // TIM10_CH1
{PB_9, TIM4, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 4, 0)}, // TIM4_CH4
//{PB_9, TIM11, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM11, 1, 0)}, // TIM11_CH1
{PB_10, TIM2, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 3, 0)}, // TIM2_CH3
{PB_13, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 1)}, // TIM1_CH1N
{PB_14, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 1)}, // TIM1_CH2N
{PB_15, TIM1, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 1)}, // TIM1_CH3N
{PC_6, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
{PC_7, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
{PC_8, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 3, 0)}, // TIM3_CH3
{PC_9, TIM3, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 4, 0)}, // TIM3_CH4
{NC, NP, 0}
};
#endif
//*** SERIAL ***
#ifdef HAL_UART_MODULE_ENABLED
WEAK const PinMap PinMap_UART_TX[] = {
{PA_2, USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
{PA_9, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{PA_11, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
{PB_6, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{PC_6, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_UART_RX[] = {
{PA_3, USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
{PA_10, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{PA_12, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
{PB_7, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{PC_7, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_UART_RTS[] = {
{PA_1, USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
{PA_12, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_UART_CTS[] = {
{PA_0, USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
{PA_11, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
{NC, NP, 0}
};
#endif
//*** SPI ***
#ifdef HAL_SPI_MODULE_ENABLED
WEAK const PinMap PinMap_SPI_MOSI[] = {
{PA_7, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
//{PB_5, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
{PB_5, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{PB_15, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PC_3, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PC_12, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_SPI_MISO[] = {
{PA_6, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
//{PB_4, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
{PB_4, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{PB_14, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PC_2, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PC_11, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_SPI_SCLK[] = {
{PA_5, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
//{PB_3, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
{PB_3, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{PB_10, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PB_13, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PC_10, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{NC, NP, 0}
};
WEAK const PinMap PinMap_SPI_SSEL[] = {
{PA_4, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
//{PA_4, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
//{PA_15, SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
{PA_15, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
{PB_9, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{PB_12, SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
{NC, NP, 0}
};
#endif
//*** No CAN ***
//*** No ETHERNET ***
//*** No QUADSPI ***
//*** USB ***
#ifdef HAL_PCD_MODULE_ENABLED
WEAK const PinMap PinMap_USB_OTG_FS[] = {
#ifndef ARDUINO_CoreBoard_F401RC
{PA_8, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_SOF
{PA_9, USB_OTG_FS, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, GPIO_AF_NONE)}, // USB_OTG_FS_VBUS
{PA_10, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_ID
#endif
{PA_11, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_DM
{PA_12, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_DP
{NC, NP, 0}
};
#endif
//*** No USB_OTG_HS ***
//*** SD ***
#ifdef HAL_SD_MODULE_ENABLED
WEAK const PinMap PinMap_SD[] = {
{PB_8, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D4
{PB_9, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D5
{PC_6, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D6
{PC_7, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D7
{PC_8, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D0
{PC_9, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D1
{PC_10, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D2
{PC_11, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D3
{PC_12, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, GPIO_AF12_SDIO)}, // SDIO_CK
{PD_2, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, GPIO_AF12_SDIO)}, // SDIO_CMD
{NC, NP, 0}
};
#endif