definitions of the LC3 instruction set architecture (ISA) (do not modify) More...
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Data Structures | |
| struct | inst_info |
Macros | |
| #define | LC3_WORD unsigned short |
| #define | LC3_MEM_SIZE 65538 |
| #define | LC3_NUM_REGS 8 |
| #define | RETURN_ADDR_REG 7 |
Typedefs | |
| typedef enum opcode_t | opcode_t |
| typedef enum inst_field | inst_field_t |
| typedef enum inst_format | inst_format_t |
| typedef struct inst_info | inst_info_t |
Enumerations | |
| enum | opcode_t { OP_BR = 0, OP_ADD, OP_LD, OP_ST, OP_JSR, OP_AND, OP_LDR, OP_STR, OP_RTI, OP_NOT, OP_LDI, OP_STI, OP_JMP_RET, OP_RESERVED, OP_LEA, OP_TRAP, NUM_OPS } |
| enum | inst_field { FMT_R1 = 0x001, FMT_R2 = 0x002, FMT_R3 = 0x004, FMT_CC = 0x008, FMT_IMM5 = 0x010, FMT_IMM6 = 0x020, FMT_VEC8 = 0x040, FMT_ASC8 = 0x080, FMT_IMM9 = 0x100, FMT_IMM11 = 0x200, FMT_IMM16 = 0x400 } |
| enum | inst_format { FMT_ = 0, FMT_RRR = (FMT_R1 | FMT_R2 | FMT_R3), FMT_RRI5 = (FMT_R1 | FMT_R2 | FMT_IMM5), FMT_CL = (FMT_CC | FMT_IMM9), FMT_R = FMT_R2, FMT_I11 = FMT_IMM11, FMT_RL = (FMT_R1 | FMT_IMM9), FMT_RRI6 = (FMT_R1 | FMT_R2 | FMT_IMM6), FMT_RR = (FMT_R1 | FMT_R2), FMT_V = FMT_VEC8, FMT_A = FMT_ASC8, FMT_16 = FMT_IMM16 } |
Functions | |
| inst_info_t * | lc3_get_inst_info (opcode_t opcode) |
This defines the details of the LC3 instruction set architecture (ISA). It is a separate file so that it could be shared by both an assembler (not yet completed) and the simulator.
| #define LC3_MEM_SIZE 65538 |
The LC3 defines a memory accessed by a 16 bit address
| #define LC3_NUM_REGS 8 |
The LC3 contains 8 general purpose register, named R0..R7
| #define LC3_WORD unsigned short |
LC3 words are 16 bits
| #define RETURN_ADDR_REG 7 |
Return address stored in R7
| typedef enum inst_field inst_field_t |
A bit field used to define the types of parameters an individual LC3 instruction may have. Each value represents a different bit in the final result. When you see C code like this, it is likely that an integer value is used to represent an "array" of up to 32 boolean values. Each value is accessed with a mask that extracts the bit of interest. See the inst_format_t below.
| typedef enum inst_format inst_format_t |
Define a combinatin of parameters an opcode may have. For example, the the BR, LD, LDI, ST and STI instructions all have two parameters. The first is a register, the second is a nine bit offset. This form stores multiple boolean values in a single integer values by using individual bits to encode information.
| typedef struct inst_info inst_info_t |
This structure stores the information about a single instruction. See the usage in lc3.c where the information for each LC3 instruction is defined.
| enum inst_field |
A bit field used to define the types of parameters an individual LC3 instruction may have. Each value represents a different bit in the final result. When you see C code like this, it is likely that an integer value is used to represent an "array" of up to 32 boolean values. Each value is accessed with a mask that extracts the bit of interest. See the inst_format_t below.
| enum inst_format |
Define a combinatin of parameters an opcode may have. For example, the the BR, LD, LDI, ST and STI instructions all have two parameters. The first is a register, the second is a nine bit offset. This form stores multiple boolean values in a single integer values by using individual bits to encode information.
| enum opcode_t |
The sixteen LC3 opcodes
| inst_info_t* lc3_get_inst_info | ( | opcode_t | opcode | ) |
Get the information for an instruction, given its opcode This is simply an access into an array of values initialized with the information for each of the LC3's sixteen instructions.
1.8.3.1