why does enabling PFCTRL cause my DMA IRQ not to happen?

Question

Posted on February 01, 2017 at 22:14I'm trying to implement a SPI slave on STMF410  using NSS_HARD_INPUTSlave should receive data of unknown length via DMASlave transmissions are of known length so master knows to keep  the SlaveSelect line active for the correct time.I'm am expecting that when SS line is released, DMA should complete and execute the DMA complete IRQBut ifI initial the DMA with the PFCTRL bit set, I no longer get the DMA  IRQ to execute.  The Tx DMA never becomes READY and is always BUSYHas anybody else tried SPI Slave with PFCTRL

waclawek.jan · Answer

Posted on February 01, 2017 at 23:07I'm trying to implement a SPI slave on STMF410Do you mean STM32F410?I'm am expecting that when SS line is released, DMA should complete and execute the DMA complete IRQWhy are you expecting that, have you seen such behaviour described in the documentation (RM0401, namely)?But ifI initial the DMA with the PFCTRL bit set, I no longer get the DMA  IRQ to execute.  That is expected. In STM32F410 there is no peripheral capable of being the Flow Controller, see RM0401 rev.2, ch. 8.3.15  Flow controller (it's written there in a cumbersome way resulting probably from automatic datasheet generation, as no peripherals listed after the 'This feature is only supported for peripherals which are able to signal the end of the transfer, that is:' sentence).There is a https://community.st.com/community/stm32-community/stm32-forum/blog/2016/12/30/2017-stm32-wish-list active currently, where you can propose STM32 hardware enhancements; don't expect they materialize anytime soon if at all.JW

Sign up

Login with SSO

Login to the community

Login with SSO

Scanning file for viruses.

This file cannot be downloaded