grdsdev/tisa

tisa is an emulator for the Tiny ISA

TISA

TISA stands for Tiny ISA.

Bulding and executing

For building the project we're using cmake.

mkdir build
cd build
cmake ..
make

Then run with: ./tisa ../input.s --dump

Supported instructions

• ADD rx, ry // rx = rx + ry
• SUB rx, ry
• DIV rx, ry
• MUL rx, ry
• BRZ rx, DES // PC += DES se rx = 0
• BRNZ rx, DES // PC += DES se rx != 0
• BRLZ rx, DES // PC += DES se rx < 0
• BRGZ rx, DES // PC += DES se rx > 0
• IBRZ rx, ADR // PC = MEM(ADR) se rx = 0
• MOV rx, ry // rx = ry
• LOADM rx, ADR // rx = MEM(ADR)
• STOREM rx, ADR // MEM(ADR) = rx
• LOADI rx, VAL // rx = VAL
• WRITE rx // printf(“%d\n”, rx)
• READ rx // scanf(“%d”, rx)
• EXIT // exit(0)

Example

int x = 0;
for (int i = 100; i > 0; i--) {
  for (int k = i; k > 0; k--) {
    x += k;
  }
}
printf("%d\n", x);

The C code above is translated to:

LOADI r1, 0
LOADI r3, 1
LOADI r2, 100
MOV r4, r2
ADD r1, r4
SUB r4, r3
BRNZ r4, -2
SUB r2, r3
BRNZ r2, -5
WRITE r1
EXIT