uProcessador

a VHDL microprocessor

This microprocessor was made for the Computer Architecture and Organization course offered at Federal University of Technology — Paraná (UTFPR), by Computer Engineering students @annaravazzi and @Maria0419.

The project was based on the Intel MCS-51 (Intel 8051) assembly, with 15 bits instructions.

INSTRUCTION SET + OPCODES

• 0x0 | 0000 -> NOP
• 0x1 | 0001 -> ADD A, Rn
• 0x2 | 0010 -> SUBB A, Rn
• 0x3 | 0011 -> ANL A, #data
• 0x4 | 0100 -> XRL A, Rn
• 0x5 | 0101 -> MOV Rn, #data
• 0x6 | 0110 -> MOV Rn, A
• 0x7 | 0111 -> CLR C
• 0x8 | 1000 -> MOV A, #data
• 0x9 | 1001 -> MOV A, @Ri
• 0xA | 1010 -> MOV @Ri, A
• 0xE | 1110 -> JC rel
• 0xF | 1111 -> AJMP addr

INSTRUCTION (14-0)

opcode (14-11)

• NOP -> --
• ADD A, Rn -> source (5-3)
• SUBB A, Rn -> source (5-3)
• ANL A, #data -> immediate (10-3)
• XRL A, Rn -> source (5-3)
• MOV Rn, #data -> immediate (10-3) | destination (2-0)
• MOV Rn, A -> destination (2-0)
• CLR C -> --
• MOV A, #data -> immediate (10-3)
• MOV A, @Ri -> memory register (5-3)
• MOV @Ri, A -> memory register (5-3)
• JC rel -> relative address (7-0) (decimal)
• AJMP addr -> address (7-0) (decimal)

REGISTERS

• x0 -> zero (constant)
• x1-x6 -> general use (r1-r6)
• x7 -> accumulator (A)