brunoagst / 8bit-c

This project is a build of an 8-bit microprocessor

8-Bit microprocessor

This project is the construction of an 8-bit microprocessor.
The processor can run on computer or raspberry pico.

Instructions

Item	Description	code
HLT	Stop processing	0x00
NOP	This instruction is used to waste time	0x01
OTI	Add accumulator value to OTR	0x02
LDA	Add UR value to accumulator	0x03
LDI	Add argument to accumulator	0x04
ADD	Add an argument to the accumulator	0x05
SUB	Subtracts argument from the accumulator	0x06
STA	Add accumulator value to UR	0x07
AND	Does the logic and between accumulator and argument	0x08
ORL	Does the logic or between accumulator and argument	0x09
XOR	Does the logic xor between accumulator and argument	0x0A
NOT	Invert the accumulator bits	0x0B
GTA	Conditional branch instruction	0x0C
IFC	Conditional branch instruction if flag c is enabled	0x0D
IFZ	Conditional branch instruction if flag z is enabled	0x0E
IFE	Conditional branch instruction if flag e is enabled	0x0F
ITI	Add ITR value to accumulator	0x10
SHR	Shift right accumulator	0x11
SHL	Shift left accumulator	0x12
CPA	Compares the accumulator with the argument	0x13
ADA	Add UR to accumulator	0x14
SBA	Subtracts UR to accumulator	0x15
ANA	Does the logic and between accumulator and UR	0x16
ORA	Does the logic or between accumulator and UR	0x17
XRA	Does the logic xor between accumulator and UR	0x18
SWA	Reversing the nibbles	0x19
PUH	Adds the accumulator value to the memory stack	0x1A
POP	Return and remove the last value from the memory stack	0x1B
CSR	Calls a function located at the address of the argument	0x1C
RET	Restores the counter to the content prior to calling the csr instruction	0x1D

Registrars

Currently has five registrars:

Item	Description
INSTRUCTION	Instruction
ADD_INSTRUCTION	Instruction address
ARGUMENT	Argument
ACC	Accumulator
ADD_ROM	Current address of rom memory
BR	8-bit registers to aid in logical operations
UR	Ten registers for the user to use
OTR	Output register
ITR	Input register

Flags

Currently has two flags:

Item	Description
CFLAG	Enabled if the result of some arithmetic operation is more than 255
ZFLAG	Enabled if accumulator is zero
EFLAG	Enabled if an accumulator is equal to the argument

Memory Stack

The memory stack has a ten levels.

Raspberry Pico

Configuration

Create the build folder and inside the folder run the command:

cmake ..

Build

make -j4