Changes between Version 76 and Version 77 of library_stdio

Timestamp:

Apr 12, 2015, 7:00:51 PM (9 years ago)

Author:

alain

Comment:

--

library_stdio

@@ -51 +51 @@
 The '''vci_mwmr_dma''' component implements two transfer modes that can be configured by the user application through dedicate system calls.
 The user application must use the ''giet_coproc_alloc()'' system call to get a private hardware coprocessor. Then it must use the ''giet_coproc_channel_init()'' system call to configure the TO_COPROC/FROM_COPROC channels.
-The coprocessor and the communication channels are activated by the ''get_coproc_run()'' system call. 
- * In '''MODE_MWMR''', each channel FSM  implements the 7 steps MWMR protocol, and transfer an "infinite" data stream, between one coprocessor port and a MWMR software FIFO in memory. The There is no transfer completion signaling, as the synchronisation is done through the MWMR FIFOs. The MWR IRQ is only asserted if a VCI error is reported in memory access. 
- * In '''MODE_DMA_IRQ''' or '''MODE_DMA_NO_IRQ''', each channel FSM transfers a single buffer between one coprocessor port and the memory. When transfer is completed, the channel FSM keep blocked until it is re-activated. 
-   - In '''MODE_DMA_IRQ''', the calling task is descheduled, after coprocessor activation, in the ''giet_coproc_run()'' system call. The transfer completion is signaled by the MWR IRQ that updates the ''_coproc_status'' / ''_coproc_channel'' variables, deactivates the coprocessor, and resumes the calling task. 
-   - In '''MODE_DMA_NO_IRQ''', the ''giet_coproc_run()'' system call returns after coprocessor activation. The user task must use the blocking ''giet_coproc_completed()'' system call that detect transfer completion by polling the coprocessor registers, and deactivates the coprocessor before returning.
-
-'''WARNING''': For a given coprocessor, all channels must be running in the same mode. If this is not the case, the result is unpredictable.
+The coprocessor and the communication channels are activated by the ''giet_coproc_run()'' system call. 
+ * In '''MODE_MWMR''', each channel FSM  implements the 7 steps MWMR protocol, and transfer an "infinite" data stream, between one coprocessor port and a MWMR software FIFO in memory. The ''giet_coproc_run()'' system call is non blocking, as the synchronisation is done through the MWMR FIFOs (no transfer completion event). The MWR IRQ is only asserted if a VCI error is reported in memory access. 
+ * In '''MODE_DMA_IRQ''' or '''MODE_DMA_NO_IRQ''', each channel FSM transfers a single buffer between one coprocessor port and the memory, and keep blocked when the transfer is completed. In both DMA modes, the user application must use the ''giet_coproc_completed()'' system call to detect global completion and report the possible addressing errors.
+   - In '''MODE_DMA_IRQ''', the calling task is descheduled, after coprocessor activation, in the ''giet_coproc_run()'' system call. It is rescheduled by the MWR IRQ signaling the global completion.  
+   - In '''MODE_DMA_NO_IRQ''', the ''giet_coproc_run()'' system call returns after coprocessor activation, and the ''giet_coproc_completed()'' system call uses a polling to detect  completion and report errors.
+
+'''WARNING''': For a given coprocessor, all channels must be running in the same mode.
 
 '''WARNING''' : For all channels, the memory buffer base address and size  must be multiple of the hardware burst size.