VME in CMS

Printable (html)
Printable  (pdf)
1 Introduction
2 VME64x in CMS
3 VMEBridges
    3.1 CAEN
        3.1.1 Technical Info
        3.1.2 Status
        3.1.3 Software
        3.1.4 Firmware
        3.1.5 Measurements
    3.2 SBS

3.1.2 Status

The optical and the USB versions of the module are available and functional. They have been tested with the HAL library which contains full support of the modules.

  • Reading large blocks with block-transfer AMs (> 8MB) causes an Error in the interface. This will be solved at the level of the VME library delivered by CAEN.
  • Interrupt handling is currently implemented in the following way: The user library provides a call which goes into a wait state until an interrupt occurs. With a bitmask the user can specify which interrupt it wants to wait for. Optionally a timeout for the wait call can be given. This implementation means that the multithreading has to be handles either at the HAL level or at the user level (the software which uses the HAL). Intterrupts have been tested by the Wisconcent group. No problem seems to exists if used with firmware revisions v1718vub_Rev0.14.rbf and higher.
  • The CAEN module is "FAST" in the sense that during a read process the slave really must have the data stable before giving the DTACK. During block transfers the address cycles arrive earlier than with the SBS (but VME compliant) If you realize that your module "does not work" with the CAEN but did work ok with the SBS, please check the timing on the VME backplane with a scope.
  • The CAEN module (6U version only) does not drive AS and DS0/1 high. This leads to slow rising edged of these signals. This is according to VME spec, but not optimal of course. For the 6U modules which CMS will use this will probably not change. Please check if this is a problem for you, and if so, please find out why. The 9U version of the module will have these lines actively driven.
last changed: 2012-10-02 comments to: Christoph Schwick