stm32官方关于SMBUS的例程 SMBus 3.0 transfers: Quick command Read/write

/** @page SMBUS_PMBUS_Test STM32L4 SMBus and PMBus example and simple test @verbatim ******************** (C) COPYRIGHT 2018 STMicroelectronics ******************* * @file SMBUS/readme.txt * @author MCD Application Team * @brief Description of the SMBus example. ****************************************************************************** * * 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. * ****************************************************************************** @endverbatim @par Example Description This example guides you through the different configuration steps by mean of HAL API to ensure SMBus and PMBus transmission and reception using Interrupt. The communication is done with 2 Boards through I2C. At the beginning of the main program the HAL_Init() function is called to reset all the peripherals, initialize the Flash interface and the systick. Then the SystemClock_Config() function is used to configure the system clock (SYSCLK) to run at 80 MHz. The I2C peripheral configuration is ensured by the HAL_SMBUS_Init() function. This later is calling the HAL_SMBUS_MspInit()function which core is implementing the configuration of the needed I2C resources according to the used hardware (CLOCK, GPIO and NVIC). You may update this function to change I2C configuration. Example then configures the LED and User Button to control and visualize the test progress. The communication is then initiated. @par HW setup To get the example working properly two Discovery boards are needed, one to perform as host and the other to perform as device. Connect with wires SCL and SDA pins of the two boards. In case of the STM32L476G Discovery that is PB6 (PIN15 P1) and PB7 (PIN16 P1) for I2C1 and PB10 and PB11 for I2C2. Use pull-up resistors or make sure the host side has the internal pull-up configured. It is not advisable to have internal pull-up configured on more devices. To test the alert capability, interconnect the PB5 (PA8) pins as well. ___ Host BOARD _____ _____VDD _____ _____ Device Board _____ | ______________| | | |______________ | | |I2C1(I2C2) | | | | I2C1(I2C2) | | | | | R (4.7K) R | | | | | SCL |____|_________|______| SCL | | | | | | | | | | | | | | | | | | SDA |______________|______| SDA | | | |______________| |______________| | | | | | | GND|_____________________|GND | |__ STM32 Discovery ___| |__ STM32 Discovery ___| @par Configuring the example Various features and working modes of the example FW can be configured using following preprocessor defines on the host board: HOST1 – define to configure I2C1 as the bus host. If ARP is defined as well, the host will wait for “ARP notify host” command from a device. Otherwise the host will immediately attempt to send loop of test commands to the device on address that goes first in the device list (address 0x1A by default). TEST2 – replaces the default test command with a PMBus group command test. TEST3 – replaces the initial 4 test cases with PMBus extended command tests. TEST4 - TEST 4 must be defined on both sides simultaneously in order to work, it also requires DENSE_CMD_TBL active and it's setting prevent it from working with ARP. The test uses selected commands from PMBUS command table. Also the bar toggling on Host may be different that one on recieving device. TEST5 - a routine for quick non-regression test of the Zone capability. Requires PMBUS13 Device side specific preprocessor defines: DEV_PSA – Device has a persistent address. SMB1 – define to configure I2C1 to SMBus (Port B) SMB2 – define to configure I2C2 to SMBus (Port A) Also, following preprocessor define switches influence not only the example but the stack itself: DEV_DIS – Device is discoverable – reacts to general ARP calls on default address. ARP – define to enable the automatic address resolution protocol execution in the code startup. Push user button then to proceed to regular tests. To test ARP successfully, DEV_DIS must be active on the device side. USE_PEC - Defined when ARP is defined, but usable without ARP. Forces use of packet error checking in communication. PMBUS12 - Define to include PMBus 1.2 new commands. PMBUS13 - Define to include PMBus 1.3(.1) new commands. DENSE_CMD_TBL - Switches between two methods of locating command code, the fast and the thorough. Either the command code is directly the index to the table, or a search is done. ALERT – Enables alert signal. Must be defined on both master and slave. @par Example operation The host-configured discovery board flashes a LED light as transmitting commands. The device receiving commands flashes LED (LED that flashes changes according to command code if more LED are present, same led except TEST4) for regular command or simply quietly replies in case of receive byte command of default test. User can use the host mounted blue button to cycle between commands (test cases) and device mounted blue button to send alert or notify. Examples of working test configurations: - Host configured with HOST1, TEST2, device configured with DEV_PSA, SMB1 - Host configured with HOST1, TEST4, device with TEST4, DENSE_CMD_TBL, SMB1 - Host configured with HOST1, ARP, device with DEV_DIS, ARP, SMB1 (and/or SMB2) ( UDID must be manually configured to unique numbers ) Address resolution protocol (ARP) demo requires the device to send notify to the host to get the address assigned. Then the host button is used to progress in further steps. In case of communication error the board detecting the LED blink will stop. Depending on speed settings, the LED may appear quite dim as a result of short duty cycle. @par Directory contents - SMBUS/Inc/stm32l4xx_hal_conf.h HAL configuration file - SMBUS/Inc/stm32l4xx_it.h I2C interrupt handlers header file - SMBUS/Inc/main.h Header for main.c module - SMBUS/Src/stm32l4xx_it.c