To support deterministic latency with non-power of two octets per frame
(F=3,6) the interface width towards the transport layer must be resized
to match integer multiple of frames.
e.g Input datapath width = 4; Output datpath width = 6;
for F=3 one beat contains 2 frames
for F=6 one beat contains 1 frame
The width change is realized with a gearbox.
Due the interface width change the single clock domain core is split
in two clock domains.
- Link clock : lane rate / 40 for input datapath width of 4 octets 8b10b
- lane rate / 20 for input datapath width of 8 octets 8b10b
- lane rate / 66 for input datapath width of 8 octets 64b66b
- Device clock : Link clock * input data path width / output datapath width
Interface to transport layer and SYSREF handling is moved to device clock domain.
The configuration interface reflects the dual clock domain.
If Input and Output datapath width matches, the gearbox is no longer
required, a single clock can be connected to both clocks.
Having the same name for dac and adc TPLs creates conflict in the
address segment naming having random names associated to the segments.
This causes difficulties during scripting of the project in test bench
mode.
When only one converter is used there is no need for concatenation and
slicer cores. In that case the TPL will connect to port 0 from the
application layer.
A multi-link is a link where multiple converter devices are connected to a
single logic device (FPGA). All links involved in a multi-link are synchronous
and established at the same time. For a TX link this means that the FPGA receives
multiple SYNC signals, one for each link. The state machine of the TX link
peripheral must combine those SYNC signals into a single SYNC signal that is
asserted when either of the external SYNC signals is asserted.
Dynamic multi-link support must allow to select to which converter devices on
the multi-link the SYNC signal is propagated too. This is useful when depending
on the use case profile some converter devices are supposed to be disabled.
Add the cfg_links_disable[0x081] register for multi-link control and
propagate its value to the TX FSM.
A multi-link is a link where multiple converter devices are connected to a
single logic device (FPGA). All links involved in a multi-link are synchronous
and established at the same time. For a RX link this means that the SYNC signal
needs to be propagated from the FPGA to each converter.
Dynamic multi-link support must allow to select to which converter devices on
the multi-link the SYNC signal is propagated too. This is useful when depending
on the usecase profile some converter devices are supposed to be disabled.
Add the cfg_links_disable[0x081] register for multi-link control and
propagate its value to the RX FSM.
The ADI JESD204 link layer cores are a implementation of the JESD204 link
layer. They are responsible for handling the control signals (like SYNC and
SYSREF) and controlling the link state machine as well as performing
per-lane (de-)scrambling and character replacement.
Architecturally the cores are separated into two components.
1) Protocol processing cores (jesd204_rx, jesd204_tx). These cores take
care of the JESD204 protocol handling. They have configuration and status
ports that allows to configure their behaviour and monitor the current
state. The processing cores run entirely in the lane_rate/40 clock domain.
They have a upstream and a downstream port that accept and generate raw PHY
level data and transport level payload data (which is which depends on the
direction of the core).
2) Configuration interface cores (axi_jesd204_rx, axi_jesd204_tx). The
configuration interface cores provide a register map interface that allow
access to the to the configuration and status interfaces of the processing
cores. The configuration cores are responsible for implementing the clock
domain crossing between the lane_rate/40 and register map clock domain.
These new cores are compatible to all ADI converter products using the
JESD204 interface.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Laszlo Nagy
Istvan Csomortani
Lars-Peter Clausen