M75 (MEN MIKRO)

The M75 is based on the M-Module ANSI mezzanine standard. It can be used as an I/O extension in any type of bus system, i.e. CPCI, PXI, VME or on any type of stand-alone SBC. Appropriate M-Module carrier cards in 3U, 6U and other formats are available from MEN or other manufacturers. The M75 is a fast dual serial interface with a data transfer rate of up to 2Mbits/s per channel, using RS422 line transceivers in full-duplex mode or RS485 line transceivers in half-duplex mode. The two channels are optically isolated from each other and from the system. The Serial Communication Controller (85C30 compliant) of the M75 is implemented in an FPGA. It supports both asynchronous and synchronous transmission, also allowing the HDLC/SDLC protocol. To achieve higher data rates without burdening the system with interrupts, the M75 has four asynchronous external data FIFOs. The FIFOs have a depth of 2kB in each direction and support simultaneous reading and writing. The M75 supports RS422/485 line levels at the front and alternatively TTL signals via the carrier board connector (e.g. VME P2, CPCI J4/J5). Using MEN's SA-adapters (serial interface adapters) multiple combinations of signal levels -- TTL, RS232 etc. -- may be implemented via the backplane.