Busy Box and related

Overview

Traditionally the Fee in ALICE sub-detectors indicates when its buffers are full and cannot handle further triggers from the CTP. This is either done directly or through the FANIN module to the LTU with a busy signal.

Due to dense cabling, four of the ALICE sub-detectors (TPC, PHOS, FMD and EMCal), utilize a BusyBox to keep track of free buffers in their Fec. The BusyBox asserts the busy signal to the LTU when one or more of these conditions are true:

1. Buffers in Fec are full
2. Upon receiving a trigger sequence from TTC
3. When the TTC sends a global reset to the Fee

The busy signal is de-asserted when one or more FEC buffers are freed

The BusyBoxes are located in the DAQ counting rom.

Version history

1.0

• Magne Munkejord

1.01 (~may 2009)

• Firmware version register added to 0x2015
• Busy Controller module updated to handle orphan messages

Download Section

Specification document:
user_guide_busybox.pdf

Source files:
SVN database

BusyBox firmware:

• Version 1.01:
| busybox_fpga1.bit | busybox_fpga2.bit | busybox_fpga1_solo.bit
RCU Trigger Receiver Module Master Thesis, Magne Munkejord PhD Thesis, Johan Alme User Guide BusyBox, Rikard Bølgen