Updates.

applications/lofar2/doc/prestudy/station2_sdp_160MHz.txt

@@ -7,6 +7,7 @@ Daarvoor moeten we een component toevoegen die gebruik maakt van de 25MHz crysta
 Na clock wissel 200M --> 160M of andersom is het volgende nodig en genoeg voor SC richting SDP:
 
 * doe FPGA_boot_image_RW zodat de images opnieuw geladen worden
+* poll tot bijv FPGA_firmware_version_R de juiste naam weergeeft (dan is image op)
 * write FPGA_pps_expected_cnt_RW met 160M of 200M
 
 JDM: Als ik FPGA_boot_image_RW schrijf naar de huidige waarde, hoe kan ik dan zien of de FPGAs gereboot zijn? wachten op TR_FPGA_communication_error_R == False oid?

applications/lofar2/doc/prestudy/station2_sdp_transient_buffer.txt

-Detailed design: Transient Buffer function (LIFT)
+Detailed design: Transient Buffer (TBuf) function for LIFT project
+
+
+0) MVP = minimal viable product:
+1) DDR4 memory per receiver input
+2) Meeting EK-BH 24 okt 2022 [2]
+3) TBB (Transient Buffer Board) LOFAR1
+4) TBuf (Transient Buffer) Design
+5) TBuf ICD SC-SDP, SDPTR-SDPFW
+6) TBuf ICD STAT/SDP-CEP
+7) Transient detection (TDet) Design
+
 
 References:
+
 [1] LIFT requirements: https://plm.astron.nl/polarion/#/project/LOFAR2System/wiki/Overview%20pages/LIFT%20Reference
+    https://git.astron.nl/desp/hdl/-/blob/L2SDP-857/applications/lofar2/doc/prestudy/lift_sdp_transient_buffer.txt
+
 [2] https://support.astron.nl/confluence/display/L2M/2022-10-24+LIFT+meeting+notes
+    https://support.astron.nl/confluence/display/L2M/2023-02-08+LIFT+meeting+notes
+
 [3] L1 LOFAR2 Decision: Transport of buffer data from Station to CEP, https://support.astron.nl/confluence/pages/viewpage.action?pageId=94766339
+
 [4] LOFAR1 TBB: https://support.astron.nl/confluence/display/L2M/Temporary+storage+of+documents+and+papers
+    https://support.astron.nl/confluence/pages/viewpage.action?spaceKey=L2M&title=Temporary+storage+of+documents+and+papers&preview=/17335979/23069390/TBB_Design_Description_ASTRON_SDD_047.pdf
+
 [5] LOFAR2 PDR: https://support.astron.nl/confluence/pages/viewpage.action?spaceKey=L2M&title=2019-07-01+Meeting+notes%3A+Transient+Buffer+functionality
 
+
+
 0) MVP = minimal viable product:
-  - omvat TB, maar nog niet Transient Detectie (TDet)
+  - omvat TBuf, maar nog niet Transient Detectie (TDet)
   - needs ring, because 6 antennas per event are typically not connected to one FPGA
 
 
@@ -35,8 +56,8 @@ In LOFAR12060 [1] time series data en pulse data, wat is pulse data :
 Hoe streng is de 3.33 s, mag 3.2 s ook ?
 Gebruik een 16 GByte module per FPGA, zodat uitbreiding naar 6.66 s mopgelijkl is door beide slots the gebruiken
 Uitlezen per receiver input, zodat uitlezen van een deel vd receiver inputs mogelijk is (bijv 12 vd 192 in [1])
-Defineer TB functie per receiver input:
-. zodat de TB functie makkelijk uitbreidbaar is naar meer inputs en naar meer DDR4 modules.
+Defineer TBuf functie per receiver input:
+. zodat de TBuf functie makkelijk uitbreidbaar is naar meer inputs en naar meer DDR4 modules.
 . data capture en uitlezen van een receiver input onafhankelijk kan van de andere receiver inputs
 
 
@@ -60,3 +81,215 @@ Design decision 16GByte DDR4 na L2SDP-854, 850
 - Buffer lengte versus nof antennes
 - Self trigger
 
+
+3) TBB (Transient Buffer Board) LOFAR1
+- From 2.3 in [4]
+  . uses 2048 Byte pages
+  . addressed based -> typically for write/store
+    time based -> typically for read/retriev
+  . 16 channels free size --> not fragmented, not overlap, nof pages/channel, circular
+
+
+4) Transient Buffer (TBuf) Design
+
+- buffer raw data, no need to buffer subbands
+
+- choose fixe 14b data, so not e.g. 8 Msbits for lighting and 8 Lsbits for
+  cosmic ray. Always using full W_adc = 14b makes design and usage more clear.
+
+- Station --> CEP --> Data Writer
+  . SDP output UDP directly to CEP or to LCU so that LCU can pass it on via TCP, to
+    recover from data loss
+  . SDP output via 10GbE
+  . SDP CP for speed dial (= throttle) output, to avoid data loss
+
+- treat all signal inputs independently (even though X and Y are always needed together)
+
+- timing
+  . Use sample sequence number (SSN) or mem_bsn:
+    - SSN increments by nof_samples_per_page = 8176
+    - mem_bsn increments by 1 per page, so per block of nof_samples_per_page = 8176.
+  . SSN counts sample periods (5 ns) since t_epoch = 1970, can fit
+      2**64 / (365.25 * 24 * 3600 / 5e-9) > 2922 years
+  . TBuf uses sop and eop to mark nof_samples_per_page = 8176
+  . TBuf does not need sync ?
+  . Start SSN or mem BSN at same time as SDP BSN by FPGA_processing_enable_RW.
+
+- CP per signal input buffer
+  . flexible start and end address (so flexible buffer time per signal input)
+  . freeze, unfreeze
+  . no need to whipe (zero) buffer contents after unfreeze ?
+
+- State
+  . rst --> stop <--> record
+
+- Block diagram:
+
+  per si: pack 14b to 64b --> add mem hdr (= ssn or bsn) --> add crc --> pack 64b to 256b
+
+  mux 12 si to 1 --> mux with + 1 MM --> write to DDR4
+
+  read from DDR4 --> demux to
+       . 1 MM
+       . 1 retrieve --> unpack 256b to 64b --> check CRC --> add output hdr --> dump
+
+- support MP on buffer state
+  . signal input index
+  . frozen, buffering, reading
+  . start address (time), end address (time)
+
+- Provide direct MM access interface to DDR4
+  . New access multiplexer component to interface with io_ddr with:
+    . write 12 signal input streams for TBuf recording + 1 MM write stream
+    . read 1 stream for TBuf readout + 1 MM read stream
+  . Write multiplexer for 12 + 1 = 13 inputs will take ~100 M20K,
+    because it needs to multiplex and FIFO streams of 256 bit each and
+    256 bit requires 256 /40 = 7 M20K in parallel, so 13 * 7 = 91 M20K.
+  . One M20K = 20b * 1024 words = 40b * 512 words, 512 words of 256b =
+    16 kByte, so FIFO can fit (almost) two 8 kB payloads, which seems
+    sufficient.
+
+- Use 1 DDR4 module / FPGA
+  . Because 16GB is enough for T_tbuf = 3.3 s
+  . 1 DDR4 @ 200MHz yields 200MHz * 256b/8b = 6.4 GB/s maximum write
+    access. Samples data from 12 ADCs is 12 * 200MHz * 16b/8b = 4.8 GB/s.
+    Hence the TBuf function then uses 4.8 / 6.4 = 0.75 of the capacity,
+    which is fine and leaves sufficient spare capacity for some buffer
+    read out, because 10Gbps / 8b = maximum 1.2 GB/s.
+  . If we would use 2 DDR4 modules/ FPGA, then treat them as one big
+    buffer with extended address space by DDR4 II, so use them
+    sequentially, rather than in parallel, and to still have full
+    freedom of allocating memory space to signal inputs.
+
+- support partial dump
+  . lightning >~ 1 s, cosmic ray >~ 1 ms
+  . dump t0 - t1
+  . dump last dt
+
+- packetize voor buffer write of na buffer read? --> voor
+  . packtetize at 64b or 256b ?
+  . 16b -> 64b packetize --> 64b --> 256b store
+  . data in buffer must have CRC --> 64b CRC ?
+  . ddr page packet format: SSN + packed data + CRC
+    - 8 KByte page to have integer number of pages (= slots) in 16G memory, so
+      that DDR4-I can wrap without a gap or extend to DDR-II without a gap.
+    - 14b packed data
+    - SSN = 64b = 8B
+    - CRC = 64b = 8B
+    - 8K - 8 - 8 = 8192 - 16 = 8176 B / 14b = 4672 samples per page
+    - 4672 * 5 ns = 23.36 us per page, so ~42.8 pages / ms
+
+
+- dp_offload_tx header is the same for all 12 signal inputs, only si differs,
+  so create one header for all and modify si field to save logic and RAM
+  . readout 1 page per tx packet
+  . add additional eth/ip/udp header and application header
+  . send packed 14b data
+
+- 12 input multiplexer with 12 x 256b in and 256b out to write 256b words @ 200 MHz
+- use SSN as timestamp, SSN = BSN * N_fft, so can be derived from bsn_source BSN,
+  or do we need a dp_ssn_source.vhd?
+
+- unb2c_test_ddr_16G resource usage
+  . git/hdl/boards/uniboard2c/designs/unb2c_test/revisions/unb2c_test_ddr_16G/unb2c_test_ddr_16G_resource_usage.jpg
+  . per module:
+    wr_fifo 13 M20K
+    tech_ddr 9 M20K
+    rd_fifo  4 M20K
+    diag db  0 M20K
+    diag bg  0 M20K
+    --> Total 26 M20K/DDR4 module
+  . board common:
+    MMM : 69 M20K voor Nios memory
+    ctrl: 42 M20K voor MMAP ROM en 1GbE
+
+- store and send 14b packed data
+  . so do not use 16b (with 2b sign extension), to optimize for memory usage and
+    transport capacity (at the expense of requiring tools to observe the payload
+    contents).
+  . store application packet with CRC in DDR4
+  . store packed 14b data for 16/14 = 1.14 more buffer space (3.3s --> 3.8s)
+  . send unpacked 16b data to CEP with new CRC
+  . CRC = 64b, header multiple of 64b, nof samples per payload multiple of 64b
+
+- Maximum number of packets per dump
+  . max memory size 16GB
+  . max payload size 8kB
+  --> 16G / 8k = 2M packets --> log2(2M) = 21b
+  . use packet serial number, instead of sop, eop bit fields, to show progress of
+    the packet dump to CEP
+  . allocate start_page/nof_pages per si to memory, wrap at max memory size
+    circular buffer per si, wrap after nof_pages
+    keep track of nof_recorded pages, when > nof pages then circular buffer is
+      full and carries only fresh data
+    keep track of ssn + page index of last recorded page
+
+
+
+5) TBuf ICD SC-SDP, SDPTR-SDPFW
+
+- Control Points (CP):
+  . FPGA_tbuf_alloc_RW [pn][si] --> start page, nof_pages (or as seperate CP?)
+    - nof_pages = 0 means si has no buffer, > 0 means si has buffer
+  . FPGA_tbuf_record_RW [pn][si] --> start/continue (True) or stop (= freeze) (False) recording
+  . FPGA_tbuf_retrieve_RW --> pn, si, ssn, nof_pre_pages, nof_post_pages (or as seperate CP?)
+    - allow only retrieve from one (pn, si) at a time
+    - total nof pages = nof_pre_pages + 1 (pointed by ssn) + nof_post_pages
+  . FPGA_tbuf_output_hdr_eth_destination_mac_RW
+  . FPGA_tbuf_output_hdr_ip_destination_address_RW
+  . FPGA_tbuf_output_hdr_udp_destination_port_RW
+  . FPGA_tbuf_output_enable_RW
+
+- Monitor Points (MP):
+  . FPGA_tbuf_total_nof_pages_R --> 16G / 8k = 2M
+  . FPGA_tbuf_page_size_R  --> 8 kByte
+  . FPGA_tbuf_nof_samples_per_page_R  --> 8176
+  . FPGA_tbuf_page_period_R  --> 23.36 us
+  . FPGA_tbuf_recording_R [pn][si]
+  . FPGA_tbuf_retrieving_R [pn][si]
+  Maybe:
+  . FPGA_tbuf_last_page [pn][si] --> index of last recorded page
+  . FPGA_tbuf_last_ssn [pn][si] --> ssn of last recorded page
+  . FPGA_tbuf_nof_recorded_pages[pn][si] --> number of fresh recorded pages <= alloc nof_pages
+
+
+
+6) TBuf ICD STAT/SDP-CEP
+
+- application header fields:
+  . 8b marker
+  . 8b version_id
+  . 16b station_id
+  . 32b source_info
+    - 1b antenna_band_index
+    - 1b nyquist_zone_index
+    - 1b f_adc --> sample period is 5 ns or 6.25 ns
+    - 1b memory_error --> based on DDR4 read CRC
+    - 5b sample_width --> 14b
+  . 8b signal_input_index
+  . 16b nof_samples_per_packet
+  . 24b packet serial number in current dump
+  . 24b total nof packets in current dump
+  . 64b SSN = Sample Sequence Number
+  No need for:
+    - 32b observation_id --> also not in LOFAR1
+    - 5b gn_index --> signal_input_index provides already all this information
+
+
+7) Transient detection (TDet) Design
+
+- no self triggering yet for MVP
+
+- will use Hilbert transform of real input and > 30MHz BPF
+  https://nl.mathworks.com/help/signal/ug/single-sideband-modulation-via-the-hilbert-transform.html
+  For the FIR Hilbert transformer we will use an odd length filter which is
+  computationally more efficient than an even length filter. Albeit even
+  length filters enjoy smaller passband errors. The savings in odd length
+  filters is a result that these filters have several of the coefficients that
+  are zero. Also, using an odd length filter will require a shift by an
+  integer time delay, as opposed to a fractional time delay that is required
+  by an even length filter. For an odd length filter, the magnitude response
+  of a Hilbert Transformer is zero for w=0 and w=π. For even length filers the
+  magnitude response doesn't have to be 0 at π, therefore they have increased
+  bandwidths. So for odd length filters the useful bandwidth is limited to
+  0 < w < π.