Microsequencer that requires a lot of LOAD/STORE instructions.
| Code | Instruction | Description |
|---|---|---|
| 0000 rrrrrrrr | LD | Load reg to work reg |
| 0010 dddddddd | LDI | Load immideate data to work reg |
| 0001 rrrrrrrr | ST | Store work reg to reg |
| 0100 dddddddd | CALL | Push current address to call stack and jump to (work_reg << 8) + data |
| 0101 00000000 | RET | Pop address from call stack and jump to poped address |
| 1001 dddddddd | JZ | if zero flag=1, jump to (work_reg << 8) + data |
| 1010 dddddddd | JC | if carry flag=1, jump to (work_reg << 8) + data |
| 1100 dddddddd | JO | if overflow flag=1, jump to (work_reg << 8) + data |
| 1000 dddddddd | JMP | Jump to (work_reg << 8) + data |
Note: r=register address, d=(immideate) data
| Address | Name | Description |
|---|---|---|
| 0 | A | Register A, used as an argument to be input to ALU. Can be used as a temporary register |
| 1 | B | Register B, used as an argument to be input to ALU. Can be used as a temporary register |
| 2 | FLAGS | Flags according to the result of ALU execution |
| 3 | ALU OP/RESULT | Set the ALU OP code to be executed by the ST instruction; execute the ALU by the LD instruction and return the result |
| 4-255 | User defined area |
| Op code | OP | Description | O | C | Z |
|---|---|---|---|---|---|
| 0000 0000 | AND | A and B | R | R | X |
| 0000 0100 | NAND | A nand B | R | R | X |
| 0010 0000 | OR | A or B | R | R | X |
| 0010 0100 | NOR | A nor B | R | R | X |
| 0010 1100 | NOT | not A | R | R | X |
| 0100 0000 | XOR | A xor B | R | R | X |
| 0100 0100 | XNOR | A xnor B | R | R | X |
| 1000 0000 | ADD | A + B | X | X | X |
| 1000 0001 | ADC | A + B + carry | X | X | X |
| 1000 0010 | SUB | A - B | X | X | X |
| 1000 0011 | SBC | A - B - !carry | X | X | X |
| 1010 0000 | SHL | A << 1 | R | X | X |
| 1010 0001 | SHCL | A << 1 carry -> result[0] | R | X | X |
| 1100 0000 | SHR | A >> 1 | R | X | X |
| 1100 0001 | SHCR | A >> 1 carry -> result[7] | R | X | X |
| 1110 0000 | SAR | A >> 1 MSB -> result[7] | R | X | X |
X = set or cleared according to result
R = restored from previously saved value
- 10 + 5
; A <- 10
0010 0000 1010: LDI 10
0001 0000 0000: ST A
; B <- 5
0010 0000 0101: LDI 5
0001 0000 0001: ST B
; ALU <- ADD
0010 1000 0000: LDI ADD
0001 0000 0011: ST ALU
; work_reg <- A + B
0000 0000 0011: LD ALU
$ python ldstasm.py input.asm -o output.[mem|v]
- KFMMC-V2 (https://github.com/kitune-san/KFMMC_V2) - Multi media card access controller