Visual X-TOY Machine（普林斯顿）- 第二列的含义

Question

普林斯顿大学的视觉X-TOY机器模拟器- Download link - Document

乘法示例：

program Multiply with stdin/stdout
// Input:    integers a and b
// Output:   integer c = a * b
// Remarks:  inefficient
// -----------------------------------------------------------------------------
10: 8AFF   read R[A]                     
11: 8BFF   read R[B]                     

12: 7C00   R[C] <- 0000                  
13: 7101   R[1] <- 0001                  

14: CA18   if (R[A] == 0) goto 18        while (a != 0) {
15: 1CCB   R[C] <- R[C] + R[B]              c += b
16: 2AA1   R[A] <- R[A] - R[1]              a--
17: C014   goto 14                       }

18: 9CFF   write R[C]                    
19: 0000   halt

第二列的含义或功能是什么（四位十六进制像CA18)？例如，我如何使用 Language Reference:

添加新行

INSTRUCTION FORMATS

             | .... | .... | .... | .... |
  Format 1:  |  op  |  d   |  s   |  t   |
  Format 2:  |  op  |  d   |     imm     |


ARITHMETIC and LOGICAL operations
    1: add            R[d] <- R[s] + R[t]
    2: subtract       R[d] <- R[s] - R[t]
    3: and            R[d] <- R[s] & R[t]
    4: xor            R[d] <- R[s] ^ R[t]
    5: shift left     R[d] <- R[s] << R[t]
    6: shift right    R[d] <- R[s] >> R[t]

TRANSFER between registers and memory
    7: load immediate R[d] <- imm
    8: load           R[d] <- mem[imm]
    9: store          mem[imm] <- R[d]
    A: load indirect  R[d] <- mem[R[t]]
    B: store indirect mem[R[t]] <- R[d]

CONTROL
    0: halt           halt
    C: branch zero    if (R[d] == 0) pc <- imm
    D: branch pos.    if (R[d] > 0) pc <- imm
    E: jump register  pc <- R[d]
    F: jump and link  R[d] <- pc; pc <- imm


R[0] always reads 0.
Loads from mem[FF] come from stdin.
Stores to mem[FF] go to stdout.

我认为它指向记忆细胞。但是根据什么？我如何确定这些值？

Answer 1

第一眼没看出来;

根据Language Reference 例如1CCB指令表示：

|   op  |   d   |   s   |   t   |
|   1   |   C   |   C   |   B   |
Operation   1: add            R[C] <- R[C] + R[B]

最终只有前两列可用。

第一列表示程序计数器。第二列表示机器指令。

Visual X-TOY Machine（普林斯顿）- 第二列的含义

Visual X-TOY Machine (Princeton) - Meaning of second column

assembly

hex

simulator

reference

machine-code