Changes between Version 5 and Version 6 of cma_driver

Timestamp:

Oct 29, 2014, 12:31:46 PM (10 years ago)

Author:

alain

Comment:

--

cma_driver

@@ -7 +7 @@
 It supports the SOCLIB ''vci_chbuf_dma'' component, that is a multi channels, chained buffer DMA controller.
 This component can be used in conjonction with the SOCLIB ''vci_frame_buffer'' to display images, or with the SOCLIB ''vci_multi_nic'' controller to transfer  RX or TX packets between NIC buffers and memory buffers.
+
+A single CMA channel transfer an ''infinite'' stream of buffers from a source ''chbuf'' to a destination ''chbuf''.
+A ''chbuf'' descriptor is a variable size circular array of 64 bits entries. Each entry is a single buffer descriptor, and
+contains a 48 bits physical address (PADDR) and a valid bit V that is 0 when the buffer is empty. 
+||1||    15   ||       48                                       ||
+||V||   unused || ------- PADDR ---------   ||
 
 The SEG_CMA_BASE address must be defined in the hard_config.h file.