#==============================================================
#
#  Name: README
#
#  Rem:  
#        EPICS IOC Application for LCLS-II superconducting LLRF
#
#  Side: None
#
#  Auth: 28-Jul-2016,          (GWBROWN)
#  Rev:  dd-mmm-yyyy, Reviewer's Name (USERNAME)
#--------------------------------------------------------------
#  Mod:
#        dd-mmm-yyyy, Reviewer's Name (USERNAME)
#          coment
#
#==============================================================
#

BUILDING: Requires code generated from register maps which are updated in scllrfApp/srcCheetah
To generate this code:
cd scllrfApp/srcCheetah
make
make copy

Then return to TOP (cd ../..) and make

This is the LLRF IOC for LLRF hardware using the network protocol from LBL for register
access. This is not part of the LCLS-II "Common Platform". The messages are formatted like:
64 bit nonce
32 bit function/address, 32 bit data
...
32 bit function/address, 32 bit data

The message must be smaller than the MTU for UDP, which is 1500 bytes, or about 175 registers.
The reply from the FPGA should be:
- The nonce echoed back unchanged
- For "read" requests, the function/address echoed back then requested 32 bit data
- for "write" requests, the function/adderss and data echoed back
(There is a bug in some firmware which adds a byte at the end of the response)

For simple cases, the code to read and write registers is generated by python Cheetah templates,
reading a dictionary/json file of register attributes.

LESS SIMPLE CASES:
CMOC fixed length waveforms are packed with the data for 8 waveforms interleaved.

32 bit function/address, 32 bit data for waveform 1
32 bit function/address, 32 bit data for waveform 2
...
32 bit function/address, 32 bit data for waveform 8
32 bit function/address, 32 bit data for waveform 1
32 bit function/address, 32 bit data for waveform 2
...

For PRC, there are up to 8 waveforms interleaved. The selection of waveforms
included are in the Trace Keep register. The trace status register bits 24 to
29 are the power of 2 for the array size, e.g. if they contain b000011, then
the waveform buffers are 2^3 = 8 registers long, or between one 8 point
waveform and 8 1 point waveforms.
Interleaving, if more than 1 waveform, is in the same manner as the CMOC waveforms.

# End of file