Using Tcl. Learning Objectives

Transcription

1 Using Tcl Learning Objectives Using the transcript program, you will translate a given specification (in DC-Shell format) into PrimeTime Tcl format. After completing this lab, you should be able to: Write a Tcl procedure that converts a given Frequency (in MHZ) into Clock period (in ns) Run the procedure, compare if the procedure produced the expected result Use the Syntax checker to debug any errors in your Tcl script Examine the command log file 30 minutes UNIT Unit 2 Using Tcl 2-1 Synopsys S36

2 Getting Started Directory structure and relevant files../libs/ Directory with Library files core_slow.db Cell library for setup check Lab2_Tcl/.synopsys_pt.setup lab2.dcsh lab2_solution.pt Directory to perform this lab PrimeTime Initialization Initial spec in DC Shell format Solution script for comparison If you need help Use the lecture material, SOLD or the Quick Reference Guide. pt_shell> help source pt_shell> help verbose source pt_shell> source help pt_shell> man source pt_shell> printvar *_path pt_shell> echo $link_path pt_shell> man link_path Remember the history commands! pt_shell> history pt_shell>! Using Tcl

3 Using Tcl Using transcript translate the specification into PT Tcl format Invoke pt_shell and enable Syntax Checking (snpstclpro) Write a procedure to convert Frequency into Period Compare result of procedure to a reference answer Use log file and update the setup file to enable syntax checking Done Your goals are to: - Convert clock frequency into clock period using a Tcl procedure - Compare the result of the Tcl procedure to a reference value and issue an appropriate message - Write out the results as you progress through the lab to a log file - Update the.synopsys_pt.setup file with the help of pt_shell_command.log file so that the check_script procedure is available upon subsequent invocations of Primetime Using Tcl 2-3

4 Background You are provided with the specification that FREQUENCY = 300 MhZ in the form of a lab2.dcsh file in DC Shell format. You will perform this lab using pt_shell. Make sure you are doing this lab in the Lab2_Tcl directory. NOTE: A solution script is provided at the end of this lab write-up. Task 1. Translate DC Shell Format into PT Tcl 1. Using the provided file lab2.dcsh invoke transcript from your Unix prompt. unix% transcript lab2.dcsh lab2.pt Question 1. Were there any errors/warnings during the translation? Compare the 2 script files lab2.dcsh and lab2.pt using an editor. The PT Tcl script (lab2.pt) should perform the following tasks: Set a variable named FREQUENCY Display the set variable Write the FREQUENCY variable to a log file my_log_file Convert the FREQUENCY variable into a PERIOD variable Append the PERIOD variable to the log file my_log_file 2-4 Using Tcl

5 Task 2. Invoke pt_shell and Enable Syntax Checking 1. Make sure that your current directory is./lab2_tcl; Invoke pt_shell to log the session to a log file. unix% pt_shell tee lab2.log 2. Load the Synopsys TclPro package containing the check_script command. pt_shell> package require snpstclpro 3. Check to see that the command check_script is availabe to you. pt_shell> help *check_script* Task 3. Add a Procedure to lab2.pt NOTE: During this task, compare your answers to those provided in the solution script at the end. 1. Using an editor, add a procedure to convert a given frequency in MHZ into clock period in ns. proc FREQ2PERIOD {freq} { return } 2. Execute the procedure on FREQUENCY and store the result into a new variable PERIOD. Display the values of FREQUENCY and PERIOD and save it to the log file my_log_file. source echo verbose lab2.pt set PERIOD echo redirect Using Tcl 2-5

6 3. Set a variable COMP for comparing the PERIOD value. (example: 10.0 / 3) Verify PERIOD matches to COMP. Issue appropriate messages. set COMP if ( ) { echo "Conversion OK -- $PER compares to $COMP" } else { echo "Conversion FAILED -- $PER not equal $COMP } Task 4. Use Syntax Checker to Check your Script 1. Run check_script on the lab2.pt file. Create an alias since you may need this command more than once. Fix any errors in the script by executing check_script as many times as needed. alias cs check_script verbose cs lab2.pt Task 5. Source your Script and Check Results 1. Note that it is only a minimum requirement to use check_script to check for syntax errors. Your script can still have some problems that may be revealed when you actually run the script. Allow the script to continue on errors in the following manner and source it: set sh_continue_on_error true ; # false by default alias so source echo verbose so lab2.pt 2. Fix any additional problems in lab2.pt script. Some common errors encountered might be: 1) Dereferencing a variable (forgetting $ before a variable name). 2) Using an undefined (or mis-typed) variable name. 3) Missing command nesting using open and close square brackets ([]). 2-6 Using Tcl

7 3. Once you have successfully sourced the script file, verify that your procedure FREQ2PERIOD exists in PT memory and display its body as follows: info procs info body FREQ2PERIOD 4. Examine the my_log_file in Unix. unix% more my_log_file Task 6. Quit Primetime and Update the Setup File 1. Quit pt_shell. pt_shell> quit 2. Use the contents of pt_shell_command.log file and update the.synopsys_pt.setup file with the following: (Copy paste) package require snpstclpro alias cs check_script verbose alias so source echo verbose set sh_continue_on_error true ; # false by default 3. The pt_shell_command.log file gets overwritten upon any subsequent invocation of Primetime. Save this log file, just in case, you need to repeat or debug later. unix% mv pt_shell_command.log Lab2_command.log Well Done! Back to the lecture. Using Tcl 2-7

8 lab2.dcsh /* */ This file was written in DC Shell format Use "transcript" to convert it into PrimeTime Tcl format FREQUENCY = 300 /* 300 MHz */ list FREQUENCY list FREQUENCY > my_log_file PERIOD = / FREQUENCY list PERIOD >> my_log_file lab2_solution.pt # # Written by : Transcript, Version Dec 11, 2001 # Date : Tue Mar 19 13:39: # # # Translation of script: lab2.dcsh # set FREQUENCY 300 ; # 300 MHz printvar FREQUENCY redirect my_log_file { printvar FREQUENCY } set PERIOD [expr { / $FREQUENCY}] redirect -append my_log_file { printvar PERIOD } proc FREQ2PERIOD {freq} { return [expr { / $freq}] } set PERIOD [FREQ2PERIOD $FREQUENCY] echo "$FREQUENCY MHz is $PERIOD ns redirect -append my_log_file \ {echo "$FREQUENCY MHz is $PERIOD ns"} set COMP [expr {10.0 /3}] if {$PERIOD == $COMP} { echo "Conversion OK -- $PERIOD compares to $COMP" } else { echo "Conversion FAILED -- $PERIOD does NOT match $COMP" } The End of Lab Using Tcl