6-Dec-2000

To modify the master clock code you must first log onto d0ol02 as
trgmgr.  You can't telnet to it.  Currently you can ssh to it, but
it's possible that in the future it may require kerberos or cryptocard
access.

On d0ol02 
----------
0)  rm -r onl_clock if necessary
    you can check if anything has changed since the last time it 
    was checked out: cvs -n -update -A
    if nothing has been modified (M), then it's not strictly necessary
    to remove onl_clock and check it out again
    note that there are some directories like bin and doc that are created
    when you do gmake config so that cvs doesn't know about them, hence
    the ? preceeding them in the update report
1)  cvs checkout onl_clock
2)  setup -q build:mv162 onl_clock
3)  cd onl_clock
4)  gmake config
5)  edit src/ioc/clkSetup.c 
    if the cvs version is clkSetup.c is current, this is sufficient
    if another version of clkSetup.c is to be used (e.g. one from
    ~trgmgr/master_clock/config_files), then first copy it to
    ~trgmgr/onl_clock/src/ioc/clkSetup.c
6)  gmake rebuild
    recently there have been occassional messages about a clock skew
    error; you can usually find a time when there is no clock skew if
    you try gmake rebuild another one or two times

If you want to put your new clkSetup.c into cvs, it is strongly
recommended that you talk to Fritz Bartlett first.  The following
procedure whould work, but we haven't been committing things to cvs on
our own so it isn't very well tested.

7)  cvs -n update -A
    to check that only clkSetup.c has changed
8)  cvs commit src/ioc/clkSetup.c
9)  type in a comment to describe the changes
10) tell Fritz that there is a new version to be released

Regardless of whether or not clkSetup.c has been committed to cvs, we
want to keep track of the versions on our own:

11) cp bin/Vx-mv162/clkSetup 
	~trgmgr/master_clock/config_files/clkSetup.vX
    and add a description of this version to the master list 
    of clock files on the web
    also copy src/ioc/clkSetup.c to 
        ~trgmgr/master_clock/config_files/clkSetup_code.vX if desired

It's also necessary to move the new executable to the boot directory
if you want to use it!

12) cd /online/ioc/m68k/mv162/d0olct106
    (for the trgmgr account, there is an alias: cdboot)
13) mv clkSetup clkSetup.old or some more descriptive name
14) cp ~trgmgr/master_clock/config_files/clkSetup.vX ./clkSetup

In terms of playing with the sequencer and the PCC, there are some
files in onl_clock/src/ioc that list the available functions: clkPcc.c
and clkSeq.c.  Note, however, that you then need to include clkPcc.h
and clkSeq.h as appropriate (see
~trgmgr/master_clock/config_files/clkSetup_code.v33 for example).
What we have primarily been playing with are
clkSeqModeFreerunSet(seq)/clkSeqModeSyncSet(seq) and
clkPccModeFreerunSet(pcc)/clkPccModeNormalSet(pcc).  

The code is reasonably easy to follow, and adding a second sequencer
looks straight forward if you imitate what has been done for the first
sequencer.  The base address of the sequencer needs to be specified
and then the sequencer is "initialized."  This seems to do some
software initialization as well as some real hardware initialization.
The function returns a pointer to a variable of the type ClkSeqId_t.
In the case of the first sequencer, the variable is called seq and is
declared right after the function clkSetup begins.  Something similar
needs to be provided for the second sequencer.  It is this variable
which is used to talk to the sequencer in the future.  Loading the
timelines and then releasing the second sequencer should proceed as
for the first sequencer.  In ~trgmgr/master_clock/config_files, the
file clkSetup_code_2nd_sequencer.c attempts to show what needs to be
done in order to incorporate the second sequencer.  Note that the base
address for the second sequencer needs to be set to something sensible
and that the timelines need to be programmed.