add readme

README.md

@@ -0,0 +1,37 @@
+## What is this?
+This is project of reverse engineering Ncompunting L230 PCB (rev 1.4).
+
+[![photo](images/top-small.jpg)](images/top.jpg)
+
+## What is there?
+* *cpld/* - template for CPLD firmware for Quartus
+* *fpga/* - template for FPGA firmware for Quartus
+* *pcb/*- simplified schematic in Kicad format
+* *doc/*- some datasheets for used chips
+
+## Main chips
+* FPGA: EP1C12Q240C8N
+* CPLD: EPM3128ATC100-10N
+* Flash: AT45DB041B
+* SDRAM: IS42S32400D-7TL
+* Ethernet: RTL8201CL
+* Audio input: PCM1808
+* Audio output amplifier: LM358
+
+## Programming
+Programming header J1 have this pinout:
+
+| # | Pin    | Function |
+| - | -      | -        |
+| 1 | MAX-62 | TCK      |
+| 2 | MAX-73 | TDO	    |
+| 3 | MAX-15 | TMS	    |
+| 4 | -      | GND      |
+| 5 | MAX-4  | TDI	    |
+
+To program FPGA on-the-fly you need:
+1. Cut MAX-73 to J1-2 trace;
+2. Connect MAX-73 to CY-155;
+3. Connect CY-147 to J1-1;
+4. Connect CY-149 to J1-2;
+5. Connect CY-148 to J1-3.