The String Crate Controller (SCC) module is a VME module that controls the DACs and readout modes on the ACC readout boards. It consists of two Xilinx chips mounted on a standard 6U VME card. Since the Xilinx chips are "easily" reprogrammed, the module is quite versatile: in BELLE, it will be used in the SVD readout, the ACC readout, and the RPC readout. Xilinx firmware and software is available to use the SCC as a VME/CAMAC interface. This is done for test purposes.
The SCC module was originally developed for the RPC readout, and hence the hardware documentation (by Kirill Korotushenko) is kept in the RPC area.
Under normal circumstances, it is NOT used to readout the ACC boards (these are read through FASTbus TDCs), although
Additional documentation on SCC-related VME and Xilinx items can be found on Eric Prebys's BELLE page.
In the ACC system, the SCC is used in conjunction with the Aerogel Counter Crate Controller (ACCC), which is a simple 3U VME board that passes the signals along to the ACC MQT readout boards. A drawing showing how the SCC and ACCC are connected is available.