STM8各种硬件资源 例程

/** @page can_example_2 CAN Example2: CAN peripheral example using interrupts @par Example description This example provides a short description of how to use the CAN peripheral. Loop back mode is used for this testing purpose, so all transmitted messages are received simultaneously. There is no need to control any external bus connection or to communicate with other external units to run this example. Main routine initials the process only and next all is going automaticaly on background. TIM4 is used to control timing of the process. A message is sent and received in regulary intervals repeatedly. The length and content of transmitted message stay always constant (field MY_MESS). The ID of the message varies for each transmit-receive cycle ordinary in 16 steps loop because an offset from 0 to 15 is added to defined ID base (MY_MESS_STID). The flashing LEDs on evaluation board signal the bus communication: LED1 ... a massage with no ID offset is transmitted LED2 ... a message with offset from 1 to 15 is transmitted LED3 ... not used LED4 ... a message is received (passed the filters) Optionally four different filter settings of incoming messages can be selected in dependency on definition of symbols for filter and scale mode in configuration section. Input filters can be switched between list and mask mode, filter scale can vary between 8 and 16 bits. When 8 bit scale and list mode are selected (ID_SCALE_8 and ID_LIST_MODE are defined) only messages with offset form 0 to 7 are received. The rest from 8 to 15 are not received. That is why the bits STID0, STID1 and STID2 are masked for 8 bits scale. The same scale in masked mode (ID_MASK_MODE is defined) can receive all messages because STID3 is masked in addition by predefined mask MY_MESS_STID_MASK, too. At 16 bits scale (ID_SCALE_16 is defined) in list mode the message with no offset can be received only. The rest 15 messages are not accepted. The same scale in masked mode can receive 4 messages from 16 steps loop as the STID3 and STID2 bits are masked, so any combination at these bits is accepted. This example has been tested with ST Visual Develop (STVD) toolchain on STMS208 device for both Cosmic and Raisonance compilers. @par Directory contents - main.c Main file containing the "main" function - stm8s_it.c Interrupt vectors table @par Hardware environment STM8-EVAL evaluation board @par How to use it ? - Copy the directory content into RIDE or STVD workspace directory - Open the workspace - Rebuild all files - Load the debug session - Run program - Watch the LEDs blinking - When LEDs 2 and 4 flash together, transmitted message is accepted - You can experiment with filter settings in init_CAN routine Go to main file: CAN_example2\main.c */ /******************* (C) COPYRIGHT 2009 STMicroelectronics *****END OF FILE****/