O-SVGA - Open Source Super VGA card! - Page 1
Forum section: electronics / projects

author: L.R Johansson
author_rank: Contributor
timestamp: July 20, 2020, 04:30:20 pm
content: Hey everyone!LRJ here again, this time I'm working on the first project to really call my own - a video-card to show to employers, as my new CV, to get a job.Why a video-card? 'Cause it's fun, and I like PC components! ^^This post is a work in progress, that will be updated continously, and hopefully become more and more coherent.Project will be fully open source - but I haven't figured out the license yet - so hence why it's in this section. Might have to release it with several different ones.The O-SVGA will be based on the "Project VGA" and "GPLGPU" projects that have come before it.Performance-target:---------------------------Resolutions:320 x 200320 x 240640 x 480800 x 6001024 x 7681920 x 1080Colour-depth:2-colour16-colour32-colour256-colour8-bit16-bit24-bit32-bitBus-bandwidth:Legacy PCI 64-bit @533 MB/sCore clock - 400 MhzMemory clock - 800 MhzGame-performance:60 FPS in Quake (Fitzquake-port for Win98)60 FPS in CrocThe reason Croc is in there, is because the basic GPU inside of the GPLGPU is based on the #9 ASICS that were used for the S3 Virge cards - hence, it's the best way to test out features.Quake is of course the gold standard for Legacy 3D-gaming, so that one gets in there by default.I'm aiming for 4 copper-layers in total - the board will feature mixture of both digital and analogue circuits. (vga, USB-C (w. DP), DVI-I)Current BoM:LFE5U-85F-8BG381I Lattice FPGA - Field Programmable Gate Array ECP5; 83.6K LUTs; 1.1VW97AH2KBVX1E Winbond DRAM 1Gb LPDDR2, x32, 533MHz, -25 ~ 85CS25FL128LAGMFV013 Cypress Semiconductor NOR Flash Nor74320-9010 Molex HDMI, Displayport & DVI Connectors 29CKT RA PCB RECEPT PNL MNT THRUHOLE2129320-3 TE Connectivity HDMI, Displayport & DVI Connectors Mini Displayport Reverse OffsetLFE5U-25F-8BG256I Lattice FPGA - Field Programmable Gate Array ECP5; 24.3K LUTs; 1.1VL77HDE15SD1CH4RHNVGA Amphenol D-Sub High Density Connectors Dsub, Stamped Signal 3A, High Density, Right Angle PCB Thru Hole, FP=8.89mm (.350"), 15 Socket, Bright Tin Shell, Flash Gold, 4-40 Rear Insert, Ground Tab with Boardlock, High Temp, Nickel Shell, VGALM26420Q1XMHX/NOPB Texas Instruments Switching Voltage Regulators Dual 2.0A,High Freq Sync SD DC-DC Reg10133476-10001LF FCI / Amphenol USB Connectors 24 Cont Type C Gen 2 R/A Hybrid RcptSMF52M0JT TE Connectivity Thin Film Resistors - SMD SMF5 2M0 5%The goal is to keep the manufacturing-cost, with PCB-manufacturing included, below 150 Euro's, thereby improving on the cost of the previous projects. (although with inflation i guess it could be the same)PCB-fab:-------------------I'm designing the card aimed at JLCPCB, since according to the PCB-calculator I found online, they seem like the most sensible target, at the moment.Current Hurdles:-----------------------------In trying to reach my performance-target, I've hit a wall when it comes to translating 3.3V and 5V signal-levels on Legacy PCI to 1.1 and 1.8 V on the FPGA and DRAM.64-bits wide bus on card- 533MB/s.Need to find signal level translators that are fast enough. Any suggestions? Could I use USB or Gigabit Ethernet interface-IC's, perhaps?Signal-level Translator-candidates:---------------------------------------QS32X2384Q1G Renesas Electronics Digital Bus Switch ICs 20-bit Bus SwitchQS34X383Q3G Renesas Electronics Digital Bus Switch ICs BUS EX 32-BIT MILLIPAQSN74CBT34X245DBBR Texas Instruments Digital Bus Switch ICs 32bit FETTXS0108EQPWRQ1 Texas Instruments Translation - Voltage Levels 8-Bit Bi-directional, Level-Shifting, Voltage Translator for Open-Drain and Push-Pull Applications 20-TSSOP -40 to 125SN74ABTH32318PN Texas Instruments Universal Bus Functions 18-Bit Tri-Port Univ Bus Exchanger