练习题4.3 p.254
\sim\seq\seq-full.hcl文件内已经说的很清楚了哪些不能更改,哪些是题目要求更改的控制逻辑块.
依据家庭作业4.51的答案,在seq-full.hcl文件内更改对应的HCL描述即可 以下答案注释了#changed的就是更改部分
#/* $begin seq-all-hcl */
####################################################################
# HCL Description of Control for Single Cycle Y86-64 Processor SEQ #
# Copyright (C) Randal E. Bryant, David R. O'Hallaron, 2010 #
###################################################################### Your task is to implement the iaddq instruction
## The file contains a declaration of the icodes
## for iaddq (IIADDQ)
## Your job is to add the rest of the logic to make it work####################################################################
# C Include's. Don't alter these #
####################################################################quote '#include <stdio.h>'
quote '#include "isa.h"'
quote '#include "sim.h"'
quote 'int sim_main(int argc, char *argv[]);'
quote 'word_t gen_pc(){return 0;}'
quote 'int main(int argc, char *argv[])'
quote ' {plusmode=0;return sim_main(argc,argv);}'####################################################################
# Declarations. Do not change/remove/delete any of these #
######################################################################### Symbolic representation of Y86-64 Instruction Codes #############
wordsig INOP 'I_NOP'
wordsig IHALT 'I_HALT'
wordsig IRRMOVQ 'I_RRMOVQ'
wordsig IIRMOVQ 'I_IRMOVQ'
wordsig IRMMOVQ 'I_RMMOVQ'
wordsig IMRMOVQ 'I_MRMOVQ'
wordsig IOPQ 'I_ALU'
wordsig IJXX 'I_JMP'
wordsig ICALL 'I_CALL'
wordsig IRET 'I_RET'
wordsig IPUSHQ 'I_PUSHQ'
wordsig IPOPQ 'I_POPQ'
# Instruction code for iaddq instruction
wordsig IIADDQ 'I_IADDQ'
##### Symbolic represenations of Y86-64 function codes #####
wordsig FNONE 'F_NONE' # Default function code##### Symbolic representation of Y86-64 Registers referenced explicitly #####
wordsig RRSP 'REG_RSP' # Stack Pointer
wordsig RNONE 'REG_NONE' # Special value indicating "no register"##### ALU Functions referenced explicitly #####
wordsig ALUADD 'A_ADD' # ALU should add its arguments##### Possible instruction status values #####
wordsig SAOK 'STAT_AOK' # Normal execution
wordsig SADR 'STAT_ADR' # Invalid memory address
wordsig SINS 'STAT_INS' # Invalid instruction
wordsig SHLT 'STAT_HLT' # Halt instruction encountered##### Signals that can be referenced by control logic ####################
##### Fetch stage inputs #####
wordsig pc 'pc' # Program counter
##### Fetch stage computations #####
wordsig imem_icode 'imem_icode' # icode field from instruction memory
wordsig imem_ifun 'imem_ifun' # ifun field from instruction memory
wordsig icode 'icode' # Instruction control code
wordsig ifun 'ifun' # Instruction function
wordsig rA 'ra' # rA field from instruction
wordsig rB 'rb' # rB field from instruction
wordsig valC 'valc' # Constant from instruction
wordsig valP 'valp' # Address of following instruction
boolsig imem_error 'imem_error' # Error signal from instruction memory
boolsig instr_valid 'instr_valid' # Is fetched instruction valid?##### Decode stage computations #####
wordsig valA 'vala' # Value from register A port
wordsig valB 'valb' # Value from register B port##### Execute stage computations #####
wordsig valE 'vale' # Value computed by ALU
boolsig Cnd 'cond' # Branch test##### Memory stage computations #####
wordsig valM 'valm' # Value read from memory
boolsig dmem_error 'dmem_error' # Error signal from data memory####################################################################
# Control Signal Definitions. #
#################################################################################### Fetch Stage #################################### Determine instruction code
word icode = [imem_error: INOP;1: imem_icode; # Default: get from instruction memory
];# Determine instruction function
word ifun = [imem_error: FNONE;1: imem_ifun; # Default: get from instruction memory
];bool instr_valid = icode in { INOP, IHALT, IRRMOVQ, IIRMOVQ, IRMMOVQ, IMRMOVQ,IOPQ, IJXX, ICALL, IRET, IPUSHQ, IPOPQ, IIADDQ};#changed# Does fetched instruction require a regid byte?
bool need_regids =icode in { IRRMOVQ, IOPQ, IPUSHQ, IPOPQ, IIRMOVQ, IRMMOVQ, IMRMOVQ , IIADDQ};#changed# Does fetched instruction require a constant word?
bool need_valC =icode in { IIRMOVQ, IRMMOVQ, IMRMOVQ, IJXX, ICALL , IIADDQ}};#changed################ Decode Stage ##################################### What register should be used as the A source?
word srcA = [icode in { IRRMOVQ, IRMMOVQ, IOPQ, IPUSHQ } : rA;icode in { IPOPQ, IRET } : RRSP;1 : RNONE; # Don't need register
];## What register should be used as the B source?
word srcB = [icode in { IOPQ, IRMMOVQ, IMRMOVQ, IIADDQ } : rB;#changedicode in { IPUSHQ, IPOPQ, ICALL, IRET } : RRSP;1 : RNONE; # Don't need register
];## What register should be used as the E destination?
word dstE = [icode in { IRRMOVQ } && Cnd : rB;icode in { IIRMOVQ, IOPQ, IIADDQ} : rB;#changedicode in { IPUSHQ, IPOPQ, ICALL, IRET } : RRSP;1 : RNONE; # Don't write any register
];## What register should be used as the M destination?
word dstM = [icode in { IMRMOVQ, IPOPQ } : rA;1 : RNONE; # Don't write any register
];################ Execute Stage ##################################### Select input A to ALU
word aluA = [icode in { IRRMOVQ, IOPQ } : valA;icode in { IIRMOVQ, IRMMOVQ, IMRMOVQ , IIADDQ} : valC;#changedicode in { ICALL, IPUSHQ } : -8;icode in { IRET, IPOPQ } : 8;# Other instructions don't need ALU
];## Select input B to ALU
word aluB = [icode in { IRMMOVQ, IMRMOVQ, IOPQ, ICALL, IPUSHQ, IRET, IPOPQ , IIADDQ} : valB;#changedicode in { IRRMOVQ, IIRMOVQ } : 0;# Other instructions don't need ALU
];## Set the ALU function
word alufun = [icode == IOPQ : ifun;1 : ALUADD;
];## Should the condition codes be updated?
bool set_cc = icode in { IOPQ , IIADDQ};#changed################ Memory Stage ##################################### Set read control signal
bool mem_read = icode in { IMRMOVQ, IPOPQ, IRET };## Set write control signal
bool mem_write = icode in { IRMMOVQ, IPUSHQ, ICALL };## Select memory address
word mem_addr = [icode in { IRMMOVQ, IPUSHQ, ICALL, IMRMOVQ } : valE;icode in { IPOPQ, IRET } : valA;# Other instructions don't need address
];## Select memory input data
word mem_data = [# Value from registericode in { IRMMOVQ, IPUSHQ } : valA;# Return PCicode == ICALL : valP;# Default: Don't write anything
];## Determine instruction status
word Stat = [imem_error || dmem_error : SADR;!instr_valid: SINS;icode == IHALT : SHLT;1 : SAOK;
];################ Program Counter Update ############################## What address should instruction be fetched atword new_pc = [# Call. Use instruction constanticode == ICALL : valC;# Taken branch. Use instruction constanticode == IJXX && Cnd : valC;# Completion of RET instruction. Use value from stackicode == IRET : valM;# Default: Use incremented PC1 : valP;
];
#/* $end seq-all-hcl */