Hello,
we are designing a microcomputer named "Comet" based on the Atmel AT91RM9200 controller. All design files and software will be licensed under the GPL.
Currently the schematics is all what we have. We probably packed too much building blocks into the design. Before we cut down the design and start building the PCB it would be nice to hear what you think which optional building blocks should turn to essential. The ESS blocks are necessary for my job, the OPT blocks are nice to have, but make my design more complicated.
ESS AT91RM92000 with PQFP-208 package ESS USB host and function interface ESS 16/32-MByte Flash Memory, 16-bit ESS 64-MByte SDRAM, 16-bit ESS RTC DS1338 ESS Twin-CAN Controller 82C900 or Oki ML9620 ESS CPLD for custom tasks XCR3128XL-12TQ144C (with prototyping area) ESS Debug- and Modem-Port (2 x RS-232) ESS Single supply voltage 12 to 24 Volt, on-board voltage generation ESS CompactFlash Interface in True-IDE mode (for WLAN cards) ESS Connectors on Comet: Power, CAN, USB host/device, JTAG, RS-232, Ethernet OPT 512K SRAM (to be used instead of SDRAM, e.g. for eCos) OPT Serial Atmel Dataflash device, 8 MByte OPT Epson graphics controller S1D13706 for QVGA displays OPT Interface for simple 20x4 character LCD display OPT PS/2 keyboard and mouse connector UR6HCPS2-SP40 OPT Audio Codec and Power Amplifier WM9705 OPT LIN Subbus OPT MM/SD/DataFlash-Card Interface OPT SmartMedia Interface OPT SmartCard Interface
Another design decision which is not yet clear is the type of the expansion connector. I would like to add two connectors to the bottom of the PCB to insert Comet into some target system. The connector type ranges from VG64 (64 pins, 2.54 mm) to Hirose/Molex (120 pins, 0.8 mm). What do you think?
Thank you,
Hubert