How to flash upgrade a MT5656ZDX or MT5656ZDXV product.

1. Open a Terminal program (such as TeraTerm).
2. Set up as 115200 8N1 Hardware Flow Control.
3. Issue AT&F<CR>, responds "OK".
4. Issue ATI<CR>, responds "MT5656ZDX" or "MT5656ZDXV".
5. Issue ATI3<CR>, responds "ACF3_V2.000x-V90_P21_FSH".
6. Issue AT+FREV?<CR>, responds "C2FAX Patch - V0.04x".
7. Care should be taken to properly flash the correct file.
   For MT5656ZDX:
       Use F64Aload.S37 to upload GBQGxxxx.HEX
       Use NV8.S37 to upload GCQGxxxx.HEX.
   For MT5656ZDXV:
       Use F64Aload.S37 to upload GDQGxxxx.HEX
       Use NV8.S37 to upload GEQGxxxx.HEX.
8. Issue AT**<CR>, wait for "Download initiated .."
9. Send loader file F64Aload.S37 or NV8.S37 (depending on patch).
   In TeraTerm - File - Send File ..
10. Shows line of dots, then wait for
   "Flash loader" or
   "NV_Ram UpLoader"
11. Send new patch file. In TeraTerm - File - Send File ..
12. Shows many lines of dots, then wait for
    "Device successfully programmed"
13. Issue AT+GCI=B5<CR>, responds OK.
14. Issue AT&F&W0&W1Z<CR>, responds OK.
15. Issue ATI, ATI3 or AT+FREV? to verify new patch version.
