我已经为计数器编写了一个机器级代码，一旦达到 15，该计数器应该递增到 15，然后递减到 10，然后在达到 10 时重置为 0。
我已经在 .mif 文件中编写了这个程序。我使用了 2 个 .mif 文件，一个用于指令存储器，另一个用于数据存储器。
我觉得我没有正确编写跳转指令，因为我无法弄清楚如何编写跳转指令。
下面这段代码是指令内存代码
enter code here
--
-- Instruction Memory Initialization File
--
-- Instrucion Format:
--
-- R-Type: <6-bit Opcode>,<5-bit rs>,<5-bit rt>,<5-bit rd>,<5-bit shamt>,<6-bit funct>
-- bits (31-26) (25-21) (20-16) (15-11) (10-6) (5-0)
--
-- I-Type: <6-bit Opcode>,<5-bit rs>,<5-bit rt>,<16-bit Address>
-- bits (31-26) (25-21) (20-16) (15-0)
--File format:
-- Hex Address 3 hex nibbles (12 bits) : bit31 ...... bit0;
WIDTH=32;
DEPTH=1024;
ADDRESS_RADIX=HEX;
DATA_RADIX=BIN;
CONTENT BEGIN
--Hex Address : bit31..........................bit0;
-- | | |
000 : 10001100000000000000000000000000;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=0, offset=0
-- This is the first instruction that get's executed
-- in mips_ss CPU in DE0-Nano.
-- This is a lw instructioni. It loads r0 with data from
-- data memory location 0. Data memory location 0 is
-- preloaded with 0 , see DRAM.mif.
--
001 : 10001100000000010000000000000100;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=1, offset=4
-- This is a lw instructioni. It loads r1 with data from
-- data memory location 4. Data memory location 4 is
-- preloaded with 0, see DRAM.mif.
--
002 : 10001100000000100000000000001000;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=2, offset=8
-- This is a lw instructioni. It loads r2 with data from
-- data memory location 8. Data memory location 8 is
-- preloaded with 1, see DRAM.mif.
003 : 10001100000000110000000000001100;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=3, offset=12
-- This is a lw instructioni. It loads r3 with data from
-- data memory location 8. Data memory location 8 is
-- preloaded with 10, see DRAM.mif.
004 : 10001100000001000000000000010000;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=4, offset=16
-- This is a lw instructioni. It loads r4 with data from
-- data memory location 8. Data memory location 8 is
-- preloaded with 15, see DRAM.mif.
--
005 : 00010000100000000000000000000000;
-- |____||___||___||______________|
-- | | | |
-- beq,rs=4,rt=0, offset exit loop(addr:008)
006 : 00000000010000000000000000100000;
-- |____||___||___||___||___||____|
-- | | | | | |
-- R-type,rs=2,rt=0,rd=0,---,f=add
-- Add instructions (r-type, opcode=0, funct=100000)
-- add => rd = rs + rt
-- Therefore => r0 = r2 + r0
007 : 00001000000000000000000000000101;
-- |____||________________________|
-- | |
-- jump, Target address:address(005)
-- Decrementing to 10
008 : 00010000011000000000000000000000;
-- |____||___||___||______________|
-- | | | |
-- beq,rs=3,rt=0, offset to exit loop(addr:00B)
009 : 00000000010000010010100000100010;
-- |____||___||___||___||___||____|
-- | | | | | |
-- R-type,rs=2,rt=1,rd=5,---,f=sub
-- sub instructions (r-type, opcode=0, funct=100010)
-- add => rd = rs - rt
-- Therefore => r4 = r1 - r2
00A : 00001000000000000000000000001000;
-- |____||________________________|
-- | |
-- jump, Target address:address(addr:008)
-- Reloading when r0 == 10
00B : 10001100000000000000000000000000;
-- |____||___||___||______________|
-- | | | |
-- lw, rs=0, rt=0, offset=0
-- This is a lw instructioni. It loads r0 with data from
-- data memory location 4. Data memory location 0 is
-- preloaded with 0, see DRAM.mif.
00C : 00001000000000000000000000000101;
-- |____||________________________|
-- | |
-- jump, Target address:address(addr:005)
END;
[/代码]
下面下一个是数据存储器mif文件
[代码]
-- Data Memory Initialization File
--
--File format:
-- Hex Address 3 hex nibbles (12 bits) : bit31 ...... bit0;
WIDTH=32;
DEPTH=1024;
ADDRESS_RADIX=HEX;
DATA_RADIX=BIN;
CONTENT BEGIN
000 : 00000000000000000000000000000000;
001 : 00000000000000000000000000000000;
-- 1
002 : 00000000000000000000000000000001;
-- 10
003 : 00000000000000000000000000001010;
-- 15
004 : 00000000000000000000000000001111;
END;
该程序未按预期工作。它以 10 递增，然后随机递减。
请帮忙。我想我没有正确编写跳转指令格式。