Custom CPU architecture emulator with a custom Assembler
To build an assembly file run the jar file with the arguments java <jarfilename>.jar -asm <input> <outputbinfile>.
The assembler will compile the input Epic8 Assembly file into a flat binary that the CPU can read. Assembling a file will automatically run it afterwards.
To run a rom file, just run the jar java <jarfilename>.jar <inputbinfile> with the input binary ROM.
When running another ROM file you can press FILE > OPEN to open a new ROM file via the GUI.
By default the emulator will attempt to run a ./rom.bin file if no arguments are supplied, if this file does not exist the emulator will throw an error, as such it is recommended to run the emulator with arguments supplied.
Loading or saving a state can be done by using the Load/Save State buttons under the Emulator menu on the GUI menu bar. States saved are full serialized dumps of memory, registers, the display buffer, stack, stack pointer, program pointer etc. in one MemoryObject file.
Pausing and resuming the execution of the emulator can be achieved through the EMULATOR menu via the GUI, this can be helpful for debugging as no registers or anything in memory is modified.
A few debugging tools can be found under EMULATOR > DEBUG, these include Dumping Memory and Dumping the Registers (also includes the Porgram Pointer PC) these two debug tools dump the memory or registers while giving a live update of the current values of memory or registers. More debugging tools may be included in the future.
Execution speed can be changed under EMULATOR > EXECUTION SPEED, these options allow the user to slow down the curent execution if it is going too fast.
JMP - hex/$/label = Jump to point in memory indicated by first argument
CMD - hex = Call an interrupt indicated by the hex value'
MOV - hex/char, reg = Move hex/char into reg
PUSH - hex/char/reg = Push hex/char/reg value onto next free space on stack
POP - reg = Pop latest value on stack into reg
POPL - reg = Pop first value on stack into reg
PEEK - reg = Get latest value on stack and put into reg without popping
JNULL - reg = Check if reg's value is equal to 0x00 (NULL)
WAIT - hex = Wait hex clock cycles (Dependant on current execution speed)
ADD - reg, hex/reg2 = Set reg to reg + hex/reg2
SUB - reg, hex/reg2 = Set reg to reg - hex/reg2
DIV - reg, hex/reg2 = Set reg to reg / hex/reg2
MUL - reg, hex/reg2 = Set reg to reg * hex/reg2
INB - hex = Read 4 bytes on port hex into register K
OUTB - hex, hex2 = Write 4 bytes (hex2) to port hex
Go to validregisters.md
Programs are loaded at 0x400 and can take all the way up to 0xFFAA in the 64KB of memory.
Opcodes take 4 bytes each in memory.
The first byte of an opcode is the identifier that the CPU uses to tell what operation the next 3 bytes will be apart of.