NESEMU_sample

Renesas RX65N/RX72N Envision Kit NES Emulator

Japanese

Overview

NES (NES) emulator realized with 'RX65N/RX72N Envision Kit RX65N'

Project list

• main.cpp
• nesemu.hpp
• emu/* [NES Emulator source code]
• RX65N/Makefile
• RX72N/Makefile
• nesemu_stable.mot (Compiled Motorola format file)

Preparing the hardware

• Preparing the SD card interface (RX65N Envision Kit)

• RX65N Envision Kit: NES (compatible) pad connection For NES Pads:
  CN2( 2) P60 - White: Vcc (Power、Usually +5V, but use at +3.3V)
  CN2( 4) P61 - Brown: GND (Power、0V)
  CN2( 6) P62 - Orange: P/S (Parallel, shift switching)
  CN2( 8) P65 - Red: CLK (Clock)
  CN2(10) P73 - Yellow: OUT (Serial output)
  

• RX72N Envision Kit: NES (compatible) pad connection For NES Pads:
  Pmod1( 6) 3V3 - White: Vcc (Power、Usually +5V, but use at +3.3V)
  Pmod1( 5) GND - Brown: GND (Power、0V)
  Pmod1( 4) P51 - Orange: P/S (Parallel, shift switching)
  Pmod1( 3) P52 - Red: CLK (Clock)
  Pmod1( 2) P50 - Yellow: OUT (Serial output)

• RX65N Envision Kit: Audio connection (output from DA0 and DA1, GND level is 1.65V)

• P03_JOY_RIGHT_IRQ11 (DA0) Left output
• P05_IRQ13_SW (DA1) Right output
  Mono with NES specifications
• Pmod (10) PB6_RXD9_PMOD_10 ---> Use RXD signal
• Pmod ( 9) PB7_TXD9_PMOD_9 ---> Use TXD signal
• RXD/TXD: 115200 Baud, 8-bits, 1-Stop, No-Parity (Internal operation display etc.)

Prepare resources

• Write a file in “xxx.nes” format to the SD card.

Build method

• Make.
• Write the nesemu.mot file.

Method of operation

• Press the “SELECT” and “START” buttons simultaneously for about 2 seconds.
• A menu is displayed. Select with the up and down buttons and confirm with the A button.
• “Select NES File”, filer opens.
• "Load State x" Load NES state (change the slot with left / right buttons 0-9)
• "Save State x" Save NES state (change the slot with left / right buttons 0-9)
• Reset “Reset” NES
• Exit the "Close Menu" menu

Filer operations

• Move the file name focus with the up and down buttons.
• In the "xxx.nes" file, press the right button to select (game starts).
• If it is a directory, change to that directory.
• To go back to the directory, press the left button.
• Press A to display file information. (Press again to return)
• Press B to close the filer.

Monitor function via serial terminal connection

By connecting a USB serial device to SCI9, you can use the terminal software for easy operation. The following commands are supported

# help
    dir [xxx]       list current directory
    pwd             current directory path
    cd [xxx]        change current directory
    nes filename    Emulations for NES
    pause           Pause Emulation (toggle)
    reset           Reset NES Machine
    save [slot-no]  Save NES State (slot-no:0 to 9)
    load [slot-no]  Load NES State (slot-no:0 to 9)
    info            Cartrige Infomations
    call-151        Goto Monitor

With call-151, you can move to the monitor function and perform a memory dump inside the NES.

#call-151
$fff8.ffff
FFF8- FF FF 0C E2 20 E0 20 E0
$e020l
E020- 78       SEI
E021- D8       CLD
E022- A2 4D    LDX  #$4D
E024- 9A       TXS
E025- A9 10    LDA  #$10
E027- 8D 00 20 STA  $2000
E02A- AD 02 20 LDA  $2002
E02D- 10 FB    BPL  $E02A
E02F- A2 00    LDX  #$00
E031- 8A       TXA
E032- 95 00    STA  $00,X
E034- 9D 00 02 STA  $0200,X
E037- 9D 00 06 STA  $0600,X
E03A- 9D 00 07 STA  $0700,X
E03D- E8       INX
E03E- D0 F2    BNE  $E032
E040- A2 00    LDX  #$00
E042- BD 05 01 LDA  $0105,X
E045- DD 10 E0 CMP  $E010,X
E048- D0 0B    BNE  $E055
$0.
0000- 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
$0:1 2 3 4
$0.
0000- 01 02 03 04 00 00 00 00  00 00 00 00 00 00 00 00
$exit
#

Restriction

• Emulation is possible up to a total of programs and bitmaps of 2MBits (256K bytes).
• Even with the same configuration, you may not be able to start up a mapper (bank switching device).
• The function by the NES state does not seem to work correctly depending on the mapper (the mapper state cannot be saved).

Reference video

https://www.youtube.com/watch?v=frRI-cbzGus

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License

MIT

and

NES Emulator for G.P.L.