ILDEArch initial architecture discussion

[loco-choco]

This issue will serve as a way to document the decisions made for design of the ILDEArch architecture. Fell free to comment your ideas.

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Current ICMC architecture

From monografia_compilador.pdf and ProcessadorICMC2.pdf we can derive that the architecture has:

• 8 "common" registers (r0 -> r7)
• 16 bits addrs and 16 bits words
• 5 special registers:
  • Flag Register (FR)
  • Stack Pointer (SP)
  • Program Counter (PC)
  • Instruction Register (IR) [Internal to the micro-controller]
  • Memory Addr Register (MAR)
• internal VGA video card
• unique instructions:
  • for halting the processor (HALT)
  • for inserting break points (BREAKP)
  • for outputing to the video card (OUTCHAR)
  • for receiving keyboard input (INCHAR)
• no hardware interrupts

It has a RISC instruction set with the following 72 instructions:

Instruction	Usage	Description	Binary (16 bits per world)
Store (Direct)	store END, RX	Stores the data from RX in the memory pointed by END	110001|RX|xxx|xxx|x END
Load (Direct)	load RX, END	Reads the data pointed by END and stores in RX	110000|RX|xxx|xxx|x END
STOREI (Indirect)	storei RX, RY	Stores the data from RX in the memory pointed by RY	111101|RX|RY|xxx|x
LOADI (Indirect)	loadi RX, RY	Reads the data pointed by RY and stores in RX	111100|RX|RY|xxx|x
LOADN (Immediatly)	loadn RX, #NR	Stores #NR in RX	111000|RX|xxx|xxx|x NR
MOV	mov RX, RY	Stores the data from RY in RX	110011|RX|RY|xx|x0
MOV	mov RX, SP	Stores the data from SP in RX	110011|RX|xxx|xx|01
MOV	mov SP, RX	Stores the data from RX in SP	110011|RX|xxx|xx|11
ADD	add RX, RY, RZ	Stores result of RY + RZ in RX	100000|RX|RY|RZ|0
ADDC	addc RX, RY, RZ	Stores result of RY + RZ + Carry in RX	100000|RX|RY|RZ|1
SUB	sub RX, RY, RZ	Stores result of RY - RZ in RX	100001|RX|RY|RZ|0
SUBC	subc RX, RY, RZ	Stores result of RY - RZ + Carry in RX	100001|RX|RY|RZ|1
MULT	mult RX, RY, RZ	Stores result of RY * RZ in RX	100010|RX|RY|RZ|0
MULTC	multc RX, RY, RZ	Stores result of RY * RZ + Carry in RX	100010|RX|RY|RZ|1
DIV	div RX, RY, RZ	Stores result of RY / RZ in RX	100011|RX|RY|RZ|0
DIVC	divc RX, RY, RZ	Stores result of RY / RZ + Carry in RX	100011|RX|RY|RZ|1
INC	inc RX	Increases the value of RX by one	100100|RX|0|xxx|xxx
DEC	dec RX	Decreases the value of RX by one	100100|RX|1|xxx|xxx
MOD	mod RX, RY, RZ	Stores result of RY % RZ in RX	100101|RX|RY|RZ|x
AND	and RX, RY, RZ	Stores result of RY & RZ in RX	010010|RX|RY|RZ|x
OR	or RX, RY, RZ	Stores result of RY | RZ in RX	010011|RX|RY|RZ|x
XOR	xor RX, RY, RZ	Stores result of RY ^ RZ in RX	010100|RX|RY|RZ|x
NOT	not RX, RY	Stores result of !RY in RX	010101|RX|RY|xxx|x
ROTL	rotl RX, N	Rotates RX left N times	010000|RX|10x|NNN|N
ROTR	rotr RX, N	Rotates RX right N times	010000|RX|11x|NNN|N
SHIFTL0	shitl0 RX, N	Shifts RX to the left N times filling with 0	010000|RX|000|NNN|N
SHIFTL1	shitl1 RX, N	Shifts RX to the left N times filling with 1	010000|RX|001|NNN|N
SHIFTR0	shitr0 RX, N	Shifts RX to the right N times filling with 0	010000|RX|010|NNN|N
SHIFTR1	shitr1 RX, N	Shifts RX to the right N times filling with 1	010000|RX|011|NNN|N
CMP	cmp RX, RY	Stores to the Flag Register the result of RX = RY, RX > RY, and RX < RY	010110|RX|RY|xxx|x
INCHAR	inchar RX	Stores the ASCII representation of the current keyboard key in RX	110101|RX|xxx|xxx|x
OUTCHAR	outchar RX, RY	Stores the value of RX to the frame buffer pixel pointed by RY	110010|RX|RY|xxx|x
JMP	jmp END	Jumps to END	000010|0000|x|xxxxx END
JEQ	jeq END	Jumps to END if Equal flag is set (?)	000010|0001|x|xxxxx END
JNE	jne END	Jumps to END if Equal flag is not set (?)	000010|0010|x|xxxxx END
JZ	jz END	Jumps to END if Zero flag is set (?)	000010|0011|x|xxxxx END
JNZ	jnz END	Jumps to END if Zero flag is not set (?)	000010|0100|x|xxxxx END
JC	jc END	Jumps to END if Carry flag is set (?)	000010|0101|x|xxxxx END
JNC	jnc END	Jumps to END if Carry flag is not set (?)	000010|0110|x|xxxxx END
JGR	jgr END	Jumps to END if Greater flag is set (?)	000010|0111|x|xxxxx END
JLE	jle END	Jumps to END if Lesser flag is set (?)	000010|1010|x|xxxxx END
JEG	jeg END	Jumps to END if Equal or Greater flag is set (?)	000010|1001|x|xxxxx END
JEL	jel END	Jumps to END if Equal or Lesser flag is set (?)	000010|1010|x|xxxxx END
JOV	jov END	Jumps to END if Overflow flag is set (?)	000010|1011|x|xxxxx END
JNOV	jnov END	Jumps to END if Overflow flag is not set (?)	000010|1100|x|xxxxx END
JN	jn END	Jumps to END if Negative flag is set (?)	000010|1101|x|xxxxx END
JDZ	jdz END	Jumps to END if DivByZero flag is set (?)	000010|1110|x|xxxxx END
CALL	call END	Calls END	000011|0000|x|xxxxx END
CEQ	ceq END	Calls END if Equal flag is set (?)	000011|0001|x|xxxxx
CNE	cne END	Calls END if Equal flag is not set (?)	000011|0010|x|xxxxx
CZ	cz END	Calls END if Zero flag is set (?)	000011|0011|x|xxxxx
CNZ	cnz END	Calls END if Zero flag is not set (?)	000011|0100|x|xxxxx
CC	cc END	Calls END if Carry flag is set (?)	000011|0101|x|xxxxx
CNC	cnc END	Calls END if Carry flag is not set (?)	000011|0110|x|xxxxx
CGR	cgr END	Calls END if Greater flag is set (?)	000011|0111|x|xxxxx
CLE	cle END	Calls END if Lesser flag is set (?)	000011|1000|x|xxxxx
CEG	ceg END	Calls END if Equal or Greater flag is set (?)	000011|1001|x|xxxxx
CEL	cel END	Calls END if Equal or Lesser flag is set (?)	000011|1010|x|xxxxx
COV	cov END	Calls END if Overflow flag is set (?)	000011|1011|x|xxxxx
CNOV	cnov END	Calls END if Overflow flag is not set (?)	000011|1100|x|xxxxx
CN	cn END	Calls END if Negative flag is set (?)	000011|1101|x|xxxxx
CDZ	cdz END	Calls END if DivByZero flag is set (?)	000011|1110|x|xxxxx
RTS	rts	Returns to the instruction after the CALL	000100|xxxx|x|xxxxx
PUSH	push RX	Pushes the value of RX to the Stack	000101|RX|0|xxxxxx
PUSH	push FR	Pushes the value of FR to the Stack	000101|xxx|1|xxxxxx
POP	pop RX	Pops the Stack to RX	000110|RX|0|xxxxxx
POP	pop FR	Pops the Stack to FR	000110|xxx|1|xxxxxx
CLEARC	clearc	Clears Carry	001000|0|xxxxxxxxx
SETC	setc	Sets Carry	001000|1|xxxxxxxxx
HALT	halt	Halts the processor	001111|x|xxxxxxxxx
NOOP	noop	No opeation	000000|x|xxxxxxxxx
BREAKP	breakp	Inserts a break point (?)	001110|x|xxxxxxxxx