The CMS central hadron calorimeter DAQ system upgrade

The CMS central hadron calorimeters will undergo a complete replacement of their data acquisition system electronics. The replacement is phased, with portions of the replacement starting in 2014 and continuing through LHC Long Shutdown 2 in 2018. The existing VME electronics will be replaced with a μTCA-based system. New on-detector QIE electronics cards will transmit data at 4.8 GHz to the new μHTR cards residing in μTCA crates in the CMS electronics cavern. The μTCA crates are controlled by the AMC13, which accepts system clock and trigger throttling control from the CMS global DAQ system. The AMC13 distributes the clock to the μHTR and reads out data buffers from the μHTR into the CMS data acquisition system. The AMC 13 also provides the clock for in-crate GLIBs which in turn distribute the clock to the on-detector front end electronics. We report on the design, development status, and schedule of the DAQ system upgrades.