The dma_last_beats is used by the Avalon Memory Mapped interface
controller, to define the last burst length.
Its value get stable after the last valid data of the DMA interface, and staying
stable until the positive edge of the DMA's xfer_req.
No need to condition the transfer of this register to avalon clock
domain.
The XFER_END state defines the end of a transaction, when the entire
data set is written or read to/from the DDRx memory.
A transaction can contain multiple Avalon bursts. Make sure that the FSM
goes back into staging phase at the end of each burst; also define a
signals which indicate the end of each burst for control.
The dac_xfer_req should indicate one single thing, that the FIFO is in
read phase. Should not be affected by any signals, which indicates data
validity on any interface. (e.g. dac_valid)
This signal is not used by the device core, its main purpose is to
indicate the state of the interface for a posible intermediat processing
module.
Fix the reset of the dma_mem_waddr (write address register of the CDC
FIFO on DMA's clock domain). This solves the occasional invalid read backs after
multiple re-initialization of the PL_DDR_FIFO.
+ Build both the read and write logic around an FSM
+ Consistent naming of registers and wires
+ Add support for burst lenghts higher than one, current burst lenght
is 64
+ Fix all the bugs, and make it work (first bring up with
adrv9371x/a10soc)
By adding support for partial avalon transfers (data width < bus width),
valid data set size (DMA transfer length) will be dependent on the DMA bus
width only.
+ avl_write_transfer_done_s is a redundant net
+ specify the net state explicitly on if statements
+ to define the edge of avl_mem_fetch_wr_address signal,
its register and its second sync register should be used
The ad_mem_asym memory read interface has a 3 clock cycle delay, from the
moment of the address change until a valid data arrives on the bus;
because the dac_xfer_out is going to validate the outgoing samples (in conjunction
with the DAC VALID, which is free a running signal), this module will compensate
this delay, to prevent duplicated samples in the beginning of the
transaction.
+ all net names should have a *_s postfix
+ avl_burstcount is a constant 1, no need for an additional
register for it
+ all CDC should have two synchronization register, add
avl_last_beat_req_m2
All the hdl (verilog and vhdl) source files were updated. If a file did not
have any license, it was added into it. Files, which were generated by
a tool (like Matlab) or were took over from other source (like opencores.org),
were unchanged.
New license looks as follows:
Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
Each core or library found in this collection may have its own licensing terms.
The user should keep this in in mind while exploring these cores.
Redistribution and use in source and binary forms,
with or without modification of this file, are permitted under the terms of either
(at the option of the user):
1. The GNU General Public License version 2 as published by the
Free Software Foundation, which can be found in the top level directory, or at:
https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
OR
2. An ADI specific BSD license as noted in the top level directory, or on-line at:
https://github.com/analogdevicesinc/hdl/blob/dev/LICENSE
Istvan Csomortani
Rejeesh Kutty