。CPU 计划完结散花 。
给每个逻辑元件添加控制单元以达到，不同输入组合对应不同的输出。由于我们已实现了寄存器（一种能够记住 1byte 的单元），那么遍可以控制其允许输入/输出。
不同的原件，同一时刻的允许输入输出状态就定义了当时单元和单元之间的关系，如 A 寄存器输出，B 是输入，其他不设置，那么此刻完成了 A 寄存器向 B 寄存器传输数据的目的。如此类推。
控制单元是 CPU 的核心部件，由寄存器控制器、读写控制器及其他输入输入构成。如下：
将寄存器控制器和读写控制器接线，输入 32 位，对应位实现不同目的：
## PC
时钟下降沿（1->0) 时完成指令计数，重新计数。是控制指令周期用的。说明，W\R 是 5 位输入，通过一个 5-32 译码器转换成 0-32，可识别 32 个寄存器。
读写控制器也是 5 位输入，接寄存器控制器
A、B 是 8 位输入，OP 是 3 位，3-8 译码器，转为 1-8，可支持 8 种运算。
1=加法 2=减法 3=加 1 4=减 1 5=And 6=OR 7=XOR 8=取反
RAM 代表内存，MC 为其控制单元
通电之后，时钟定时脉动，提供给整个电路电压变化。通过 control Uinit 旁边的 ROM 中写入指令（32 位的 01 组合数），CU（control Unit）的 PC 每加 1，则指令 ROM 读取的 index +1，输入后从 CU 的 d 进入，完成对整个单元的控制。
最后对这些电路按设计转成代码，代码备注也由说明
# 寄存器，RAM=MC
MSR = 1
MAR = 2
MDR = 3
# RAM就是MC控制器
RAM = 4
IR = 5
DST = 6
SRC = 7
A = 8
B = 9
C = 10
D = 11
DI = 12
SI = 13
SP = 14
BP = 15
CS = 16
DS = 17
SS = 18
ES = 19
VEC = 20
T1 = 21
T2 = 22
# 寄存器输出到总线上
MSR_OUT = MSR
MAR_OUT = MAR
MDR_OUT = MDR
RAM_OUT = RAM
IR_OUT = IR
DST_OUT = DST
SRC_OUT = SRC
A_OUT = A
B_OUT = B
C_OUT = C
D_OUT = D
DI_OUT = DI
SI_OUT = SI
SP_OUT = SP
BP_OUT = BP
CS_OUT = CS
DS_OUT = DS
SS_OUT = SS
ES_OUT = ES
VEC_OUT = VEC
T1_OUT = T1
T2_OUT = T2
# 写入寄存器,暂时没搞懂为什么左移5位
_DST_SHIFT = 5
MSR_IN = MSR << _DST_SHIFT
MAR_IN = MAR << _DST_SHIFT
MDR_IN = MDR << _DST_SHIFT
RAM_IN = RAM << _DST_SHIFT
IR_IN = IR << _DST_SHIFT
DST_IN = DST << _DST_SHIFT
SRC_IN = SRC << _DST_SHIFT
A_IN = A << _DST_SHIFT
B_IN = B << _DST_SHIFT
C_IN = C << _DST_SHIFT
D_IN = D << _DST_SHIFT
DI_IN = DI << _DST_SHIFT
SI_IN = SI << _DST_SHIFT
SP_IN = SP << _DST_SHIFT
BP_IN = BP << _DST_SHIFT
CS_IN = CS << _DST_SHIFT
DS_IN = DS << _DST_SHIFT
SS_IN = SS << _DST_SHIFT
ES_IN = ES << _DST_SHIFT
VEC_IN = VEC << _DST_SHIFT
T1_IN = T1 << _DST_SHIFT
T2_IN = T2 << _DST_SHIFT
# 电路中11-14位作为RWC单元的输入，控制S和D的读写，软件层面确认不同时读写同一个单元
# src中的值对应的寄存器，读取其值
SRC_R = 1 << 10
SRC_W = 1 << 11
DST_R = 1 << 12
DST_W = 1 << 13
PC_CS = 1 << 14
PC_WE = 1 << 15
PC_EN = 1 << 16
PC_OUT = PC_CS
PC_IN = PC_CS | PC_WE | PC_EN
PC_INC = PC_CS | PC_WE
# ALU
_OP_SHIFT = 17
OP_ADD = 0
OP_SUB = 1 << _OP_SHIFT
# 加减1
OP_INC = 2 << _OP_SHIFT
OP_DEC = 3 << _OP_SHIFT
OP_AND = 4 << _OP_SHIFT
OP_OR = 5 << _OP_SHIFT
OP_XOR = 6 << _OP_SHIFT
OP_NOT = 7 << _OP_SHIFT
ALU_OUT = 1 << 20
ALU_PSW = 1 << 21
ALU_INT_W = 1 << 22
ALU_INT = 1 << 23
ALU_STI = ALU_INT_W
ALU_CLI = ALU_INT_W | ALU_INT
# cyc标识当前指令执行完了，需要重置微程序的pc数
CYC = 1 << 30
HLT = 1 << 31
# 二地址指令和一地址 指令
ADDR2 = 1 << 7
ADDR1 = 1 << 6
ADDR2_SHIFT = 4
ADDR1_SHIFT = 2
# 四种寻址方式
AM_INS = 0 # 立即数
AM_REG = 1 # 寄存器
AM_DIR = 2 # 内存直接寻址
AM_RAM = 3 # 寄存器间接寻址
# 控制器
import os
import assembly as ASM
import pin
dirname = os.path.dirname(__file__)
filename = os.path.join(dirname, 'micro.bin')
micro = [pin.HLT for _ in range(0x10000)]
# 跳转转移指令
CJMPS = {ASM.JO, ASM.JNO, ASM.JZ, ASM.JNZ, ASM.JP, ASM.JNP}
def compile_addr2(addr, ir, psw, index):
global micro
# 操作
op = ir & 0xf0
amd = (ir >> 2) & 3 # 3 = 011
ams = ir & 3
INST = ASM.INSTRUCTIONS[2]
if op not in INST:
micro[addr] = pin.CYC
return
am = (amd, ams)
if am not in INST[op]:
micro[addr] = pin.CYC
return
EXEC = INST[op][am]
if index < len(EXEC):
micro[addr] = EXEC[index]
else:
micro[addr] = pin.CYC
def get_condition_jump(exec, op, psw):
overflow = psw & 1
zero = psw & 2
parity = psw & 4
if op == ASM.JO and overflow:
return exec
if op == ASM.JNO and not overflow:
return exec
if op == ASM.JZ and zero:
return exec
if op == ASM.JNZ and not zero:
return exec
if op == ASM.JP and parity:
return exec
if op == ASM.JNP and not parity:
return exec
return [pin.CYC]
def get_interrupt(exec, op, psw):
interrupt = psw & 8
if interrupt:
return exec
return [pin.CYC]
def compile_addr1(addr, ir, psw, index):
global micro
global CJMPS
op = ir & 0xfc
amd = ir & 3
INST = ASM.INSTRUCTIONS[1]
if op not in INST:
micro[addr] = pin.CYC
return
if amd not in INST[op]:
micro[addr] = pin.CYC
return
EXEC = INST[op][amd]
if op in CJMPS:
EXEC = get_condition_jump(EXEC, op, psw)
if op == ASM.INT:
EXEC = get_interrupt(EXEC, op, psw)
if index < len(EXEC):
micro[addr] = EXEC[index]
else:
micro[addr] = pin.CYC
def compile_addr0(addr, ir, psw, index):
global micro
# 操作
op = ir
INST = ASM.INSTRUCTIONS[0]
if op not in INST:
micro[addr] = pin.CYC
return
EXEC = INST[op]
if index < len(EXEC):
micro[addr] = EXEC[index]
else:
micro[addr] = pin.CYC
# 2^16次方是16进制的10000
# for循环对下标就行遍历赋值，ROM列有16个，一行一条指令。
# 16位组成:ir[8]+psw[4]+cyc[4],与运算高位和低位双截断
for addr in range(0x10000):
ir = addr >> 8
psw = (addr >> 4) & 0xf
cyc = addr & 0xf
# 小于取址长度，则写入取指令，6个时钟沿
if cyc < len(ASM.FETCH):
micro[addr] = ASM.FETCH[cyc]
continue
addr2 = ir & (1 << 7)
addr1 = ir & (1 << 6)
# 取指令之后的index
index = cyc - len(ASM.FETCH)
if addr2:
compile_addr2(addr, ir, psw, index)
elif addr1:
compile_addr1(addr, ir, psw, index)
else:
compile_addr0(addr, ir, psw, index)
with open(filename, 'wb') as file:
for var in micro:
value = var.to_bytes(4, byteorder='little')
file.write(value)
print('micro instruction compile finished! ')
主要完成汇编转机器码的工作
import os
import pin
import assembly as ASM
import re
dirname = os.path.dirname(__file__)
inputFileName = os.path.join(dirname, 'program.asm')
outputFileName = os.path.join(dirname, 'program.bin')
# 代码的正则，分号是注释
annotation = re.compile(r"(.*?);.*")
# 代码
codes = []
# 标记，对应的代码
marks = {}
OP2 = {
'MOV': ASM.MOV,
'ADD': ASM.ADD,
'CMP': ASM.CMP,
'SUB': ASM.SUB,
'AND': ASM.AND,
'OR': ASM.OR,
'XOR': ASM.XOR,
}
OP1 = {
'INC': ASM.INC,
'DEC': ASM.DEC,
'NOT': ASM.NOT,
'JMP': ASM.JMP,
'JO': ASM.JO,
'JNO': ASM.JNO,
'JZ': ASM.JZ,
'JNZ': ASM.JNZ,
'JP': ASM.JP,
'JNP': ASM.JNP,
'PUSH': ASM.PUSH,
'POP': ASM.POP,
'CALL': ASM.CALL,
'INT': ASM.INT,
}
OP0 = {
'NOP': ASM.NOP,
'HLT': ASM.HLT,
'RET': ASM.RET,
'STI': ASM.STI,
'CLI': ASM.CLI,
'IRET': ASM.IRET,
}
OP2SET = set(OP2.values())
OP1SET = set(OP1.values())
OP0SET = set(OP0.values())
# 可操作的寄存器
REGISTERS = {
'A': pin.A,
'B': pin.B,
'C': pin.C,
'D': pin.D,
'SS': pin.SS,
'CS': pin.CS,
'SP': pin.SP,
}
class Code(object):
# 代码
CODE = 1
# 标记
LABEL = 2
def __init__(self, number, source: str, code_type=CODE):
self.number = number
self.source = source.upper()
self.op = None
self.dst = None
self.src = None
self.code_type = code_type
# 代码行
self.index = 0
self.prepare_source()
def get_op(self):
if self.op in OP2:
return OP2[self.op]
if self.op in OP1:
return OP1[self.op]
if self.op in OP0:
return OP0[self.op]
raise SyntaxError(self)
# 获取操作数类型和其操作值
def get_am(self, addr):
global marks
if not addr:
return None, None
if addr in marks:
# 一行代码占3个字节
return pin.AM_INS, marks[addr].index * 3
if addr in REGISTERS:
return pin.AM_REG, REGISTERS[addr]
if re.match(r'^[0-9]+$', addr):
return pin.AM_INS, int(addr)
if re.match(r'^0X[0-9A-F]+$', addr):
return pin.AM_INS, int(addr, 16)
# 匹配直接寻址，内存单元取址送出10进制
match = re.match(r'^\[([0-9]+)\]$', addr)
if match:
return pin.AM_DIR, int(match.group(1))
# 匹配直接寻址，内存单元取址送出16进制
match = re.match(r'^\[0X([0-9A-F]+)\]$', addr)
if match:
return pin.AM_DIR, int(match.group(1), 16)
# 寄存器间接寻址，即将寄存器中的值作为ROM下标取出值送出
match = re.match(r'^\[(.+)\]$', addr)
if match and match.group(1) in REGISTERS:
return pin.AM_RAM, REGISTERS[match.group(1)]
raise SyntaxError(self)
# 文本预处理，获取到指令-源操作数-目的操作数
def prepare_source(self):
if self.source.endswith(":"):
self.type = self.LABEL
self.name = self.source.strip(':')
return
# 逗号分割，如果大于2就是错误
tup = self.source.split(',')
if len(tup) > 2:
raise SyntaxError(self)
if len(tup) == 2:
self.src = tup[1].strip()
# 将指令和操作数分开
tup = re.split(r' +', tup[0])
if len(tup) > 2:
raise SyntaxError(self)
elif len(tup) == 2:
self.dst = tup[1].strip()
self.op = tup[0].strip()
# 计算指令-目的操作数-源操作数的二进制值
def compile_code(self):
op = self.get_op()
amd, dst = self.get_am(self.dst)
ams, src = self.get_am(self.src)
if src is not None and (amd, ams) not in ASM.INSTRUCTIONS[2][op]:
raise SyntaxError(self)
if src is None and dst and amd not in ASM.INSTRUCTIONS[1][op]:
raise SyntaxError(self)
if src is None and dst is None and op not in ASM.INSTRUCTIONS[0]:
raise SyntaxError(self)
amd = amd or 0
ams = ams or 0
dst = dst or 0
src = src or 0
if op in OP2SET:
ir = op | (amd << 2) | ams
elif op in OP1SET:
ir = op | amd
else:
ir = op
return [ir, dst, src]
def __repr__(self):
return f'[{self.number}] - {self.source}'
class SyntaxError(Exception):
def __init__(self, code: Code, *args, **kwargs):
super.__init__(*args, **kwargs)
self.code = code
def compile_program():
global codes
global marks
with open(inputFileName, encoding='utf8') as file:
lines = file.readlines()
# 遍历行
for index, line in enumerate(lines):
# 去掉空格符
source = line.strip()
# 去掉分号及后的备注，分号就是标识代码用的（简版）,冒号是标识LAB的
if ';' in source:
match = annotation.match(source)
source = match.group(1)
code = Code(index + 1, source)
codes.append(code)
continue
if source.endswith(":"):
codes.append(Code(index + 2, source, Code.LABEL))
continue
if not source:
continue
result = []
current = None
# 从后往前遍历代码行
for var in range(len(codes) - 1, -1, -1):
code = codes[var]
if code.code_type == Code.CODE:
current = code
result.insert(0, code)
continue
if code.type == Code.LABEL:
# 这里指向的是code的引用，后边的遍历改index不影响
marks[code.name] = current
continue
raise SyntaxError(code)
# 更新索引index
for index, var in enumerate(result):
var.index = index
with open(outputFileName, 'wb') as file:
for code in result:
values = code.compile_code()
for value in values:
if value is not None:
result = value.to_bytes(1, byteorder='little')
file.write(result)
def main():
try:
compile_program()
except SyntaxError as e:
print(f'Syntax Error at {e.code}')
print(f'program compile finished')
if __name__ == '__main__':
main()
主要定义，不同指令的电路组合状态。电路组合状态从管脚中定义的基本电路控制单元，或运算得到。
import pin
# 汇编
# 取址
FETCH = [
pin.PC_OUT | pin.MAR_IN,
pin.RAM_OUT | pin.IR_IN | pin.PC_INC,
pin.PC_OUT | pin.MAR_IN,
pin.RAM_OUT | pin.DST_IN | pin.PC_INC,
pin.PC_OUT | pin.MAR_IN,
pin.RAM_OUT | pin.SRC_IN | pin.PC_INC,
]
# 指令定义
MOV = 0 | pin.ADDR2
ADD = (1 << pin.ADDR2_SHIFT) | pin.ADDR2
SUB = (2 << pin.ADDR2_SHIFT) | pin.ADDR2
CMP = (3 << pin.ADDR2_SHIFT) | pin.ADDR2
AND = (4 << pin.ADDR2_SHIFT) | pin.ADDR2
OR = (5 << pin.ADDR2_SHIFT) | pin.ADDR2
XOR = (6 << pin.ADDR2_SHIFT) | pin.ADDR2
INC = (0 << pin.ADDR1_SHIFT) | pin.ADDR1
DEC = (1 << pin.ADDR1_SHIFT) | pin.ADDR1
NOT = (2 << pin.ADDR1_SHIFT) | pin.ADDR1
JMP = (3 << pin.ADDR1_SHIFT) | pin.ADDR1
# 条件转移
# 溢出和非溢出
JO = (4 << pin.ADDR1_SHIFT) | pin.ADDR1
JNO = (5 << pin.ADDR1_SHIFT) | pin.ADDR1
# 零和非0
JZ = (6 << pin.ADDR1_SHIFT) | pin.ADDR1
JNZ = (7 << pin.ADDR1_SHIFT) | pin.ADDR1
# 奇数和非奇数
JP = (8 << pin.ADDR1_SHIFT) | pin.ADDR1
JNP = (9 << pin.ADDR1_SHIFT) | pin.ADDR1
PUSH = (10 << pin.ADDR1_SHIFT) | pin.ADDR1
POP = (11 << pin.ADDR1_SHIFT) | pin.ADDR1
CALL = (12 << pin.ADDR1_SHIFT) | pin.ADDR1
INT = (13 << pin.ADDR1_SHIFT) | pin.ADDR1
# SUB = (2 << pin.ADDR2_SHIFT) | pin.ADDR2
# SUB = (2 << pin.ADDR2_SHIFT) | pin.ADDR2
# SUB = (2 << pin.ADDR2_SHIFT) | pin.ADDR2
# 0操作数指令
# 啥也不干
NOP = 0
RET = 1
# 中断返回
IRET = 2
# 开中断
STI = 3
# 关中断
CLI = 4
# 停止
HLT = 0x3f # 111111
INSTRUCTIONS = {
2: {
MOV: {
# 立即数寻址，将立即数放入SRC寄存器，存入DST种存放的具体寄存器（地址）中,这里只定义指令动作，具体执行之后解析
(pin.AM_REG, pin.AM_INS): [
pin.DST_W | pin.SRC_OUT,
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_W | pin.SRC_R,
],
(pin.AM_REG, pin.AM_DIR): [
pin.SRC_OUT | pin.MAR_IN,
pin.DST_W | pin.RAM_OUT,
],
(pin.AM_REG, pin.AM_RAM): [
pin.SRC_R | pin.MAR_IN,
pin.DST_W | pin.RAM_OUT,
],
(pin.AM_DIR, pin.AM_INS): [
pin.DST_OUT | pin.MAR_IN,
pin.RAM_IN | pin.SRC_OUT,
],
(pin.AM_DIR, pin.AM_DIR): [
pin.SRC_OUT | pin.MAR_IN,
pin.RAM_OUT | pin.T1_IN,
pin.DST_OUT | pin.MAR_IN,
pin.RAM_IN | pin.T1_OUT,
],
(pin.AM_DIR, pin.AM_RAM): [
pin.SRC_R | pin.MAR_IN,
pin.RAM_OUT | pin.T1_IN,
pin.DST_OUT | pin.MAR_IN,
pin.RAM_IN | pin.T1_OUT,
],
(pin.AM_RAM, pin.AM_INS): [
pin.DST_R | pin.MAR_IN,
pin.RAM_IN | pin.SRC_OUT,
],
(pin.AM_RAM, pin.AM_REG): [
pin.DST_R | pin.MAR_IN,
pin.RAM_IN | pin.SRC_R,
],
(pin.AM_RAM, pin.AM_DIR): [
pin.SRC_OUT | pin.MAR_IN,
pin.RAM_OUT | pin.T1_IN,
pin.DST_R | pin.MAR_IN,
pin.RAM_IN | pin.T1_OUT,
],
(pin.AM_RAM, pin.AM_RAM): [
pin.SRC_R | pin.MAR_IN,
pin.RAM_OUT | pin.T1_IN,
pin.DST_R | pin.MAR_IN,
pin.RAM_IN | pin.T1_OUT,
],
},
ADD: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_ADD | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW,
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_ADD | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW,
],
},
CMP: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_SUB | pin.ALU_PSW,
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_SUB | pin.ALU_PSW,
],
},
SUB: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_SUB | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_SUB | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
},
AND: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_AND | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_AND | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
},
OR: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_OR | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_OR | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
},
XOR: {
(pin.AM_REG, pin.AM_INS): [
pin.DST_R | pin.A_IN,
pin.SRC_OUT | pin.B_IN,
pin.OP_XOR | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
(pin.AM_REG, pin.AM_REG): [
pin.DST_R | pin.A_IN,
pin.SRC_R | pin.B_IN,
pin.OP_XOR | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
},
},
1: {
INC: {
pin.AM_REG: [
pin.DST_R | pin.A_IN,
pin.OP_INC | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW
],
},
DEC: {
pin.AM_REG: [
pin.DST_R | pin.A_IN,
pin.OP_DEC | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW,
],
},
NOT: {
pin.AM_REG: [
pin.DST_R | pin.A_IN,
pin.OP_NOT | pin.ALU_OUT | pin.DST_W | pin.ALU_PSW,
],
},
JMP: {
# 立即数写入到PC
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JO: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JNO: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JZ: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JNZ: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JP: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
JNP: {
pin.AM_INS: [
pin.DST_OUT | pin.PC_IN
],
},
PUSH: {
pin.AM_INS: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 读取目的寄存器的值到RAM，地址由MSR+MAR
pin.DST_OUT | pin.RAM_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
pin.AM_REG: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 读取目的寄存器的值到RAM，地址由MSR+MAR
pin.DST_R | pin.RAM_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
},
POP: {
pin.AM_REG: [
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
pin.SP_OUT | pin.MAR_IN,
# RAM读取值到目的寄存器，地址由MSR+MAR
pin.DST_W | pin.RAM_OUT,
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_INC,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
},
CALL: {
pin.AM_INS: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 保存当前pc到RAM
pin.PC_OUT | pin.RAM_IN,
# 读取目的寄存器的值PC
pin.DST_OUT | pin.PC_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
pin.AM_REG: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 保存当前pc到RAM
pin.PC_OUT | pin.RAM_IN,
# 读取目的寄存器的值PC
pin.DST_R | pin.PC_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
},
INT: {
pin.AM_INS: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 保存当前pc到RAM
pin.PC_OUT | pin.RAM_IN,
# 读取目的寄存器的值PC
pin.DST_OUT | pin.PC_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN | pin.ALU_PSW | pin.ALU_CLI,
],
pin.AM_REG: [
# 栈顶指针减一获取栈地址
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_DEC,
pin.SP_OUT | pin.MAR_IN,
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
# 保存当前pc到RAM
pin.PC_OUT | pin.RAM_IN,
# 读取目的寄存器的值PC
pin.DST_R | pin.PC_IN,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN | pin.ALU_PSW | pin.ALU_CLI,
],
},
},
0: {
NOP: [pin.CYC],
HLT: [pin.HLT],
RET: [
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
pin.SP_OUT | pin.MAR_IN,
# RAM读取值写回PC计数器
pin.PC_IN | pin.RAM_OUT,
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_INC,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN,
],
IRET: [
# 栈段地址送到MSR寄存器
pin.SS_OUT | pin.MSR_IN,
pin.SP_OUT | pin.MAR_IN,
# RAM读取值写回PC计数器
pin.PC_IN | pin.RAM_OUT,
pin.SP_OUT | pin.A_IN,
pin.SP_IN | pin.ALU_OUT | pin.OP_INC,
# 恢复MSR到代码段
pin.CS_OUT | pin.MSR_IN | pin.ALU_PSW | pin.ALU_STI,
],
STI: [
pin.ALU_PSW | pin.ALU_STI,
],
CLI: [
pin.ALU_PSW | pin.ALU_CLI,
],
}
}
下面演示汇编代码的执行。
MOV D,3;
MOV C,4;
ADD D,C;
HLT;
该代码先被汇编解析代码编译到 program.bin 的二进制文件中，加载 CPU 的 RAM，作为程序源。
然后控制器代码生成的二进制文件加载到 CPU 的 ROM 中，作为指令源。
最后，加法的输出结果是一个是 7，在 ALU 旁输出和 D 寄存器中都是。。。
