Making connections to SV generated interfaces - system-verilog

I need to make connections to ports of a SystemVerilog interface that have been generated. But I don't know what the instance names of the generated interfaces are, so I can't work out how to connect to them.
e.g., if I generate the code like this:
generate
for (genvar abc_if_inst = 0; abc_if_inst < NUM_ABC; abc_if_inst++)
abc_if if_abc (.clk(clk), .resetn(resetn));
endgenerate
How do I reference the interface signals, e.g. I'm assuming it's something like this:
.port_x (if_abc_GEN_INST_NUM.port_x),
.port_y (if_abc_GEN_INST_NUM.port_y),

It is best to put a begin-end around the content of the for-loop and apply a label. If you not use a label then a automatic label will be added as genblk suffixed with unique id number. Section 27.6 of IEEE Std 1800-2012 goes into detail explain the generate block naming works. Section 27 is all about generate blocks. One example about generate for-loops on page 753.
For your provided code, try:
generate
for (genvar abc_if_inst=0; abc_if_inst<NUM_ABC; abc_if_inst++) begin : mygen
abc_if if_abc (.clk(clk), .resetn(resetn));
end
endgenerate
Then you can connect by as:
.port_x (mygen[0].if_abc.port_x),
.port_y (mygen[0].if_abc.port_y),
// ...
.port_x (mygen[NUM_ABC-1].if_abc.port_x),
.port_y (mygen[NUM_ABC-1].if_abc.port_y),
Note that the index of mygen needs to be a constant, such as a parameter, another genvar, or hard coded value.

Related

Cimplicity Screen - one object/button that is dependent on hundreds of points

So I have created a huge screen that essentially just shows the robot status for every robot in this factory (individually)… At the very end of the project, they decided they want one object on the screen that blinks if any of the 300 robots fault. I am trying to think of a way to make this work. Maybe a global script of some kind? Problem is, I do not do much scripting in Cimplicity, so any help is appreciated.
All the points that are currently used on this screen (to indicate a fault) have very similar names… as in, the beginning is the same… so I was thinking of a script that could maybe recognize if a bit is high based on PART of it's string name characteristic. The end will change a little each time, but I am sure there is a way to only look for part of a string and negate the rest. If the end has to be hard coded, that's fine.
You can use a Python script in Cimplicity.
I will not go into detail on the use of python in Cimplicity, which is well described in the documentation indicated above.
Here's an example of what can be done... note that I don't have a way to test it and, of course, this will work if the name of your robots in the declaration follows the format Robot_1, Robot_2, Robot_3 ... Robot_10 ... Robot_300 and it also depends on the Name and the Type of the fault variable... as you didn't define it, I imagine it can be an integer, with ZERO indicating no error. But if you use something other than that, you can easily change it.
import cimplicity
(...)
OneRobotWithFault = False
# Here you get the values and check for fault
for i in range(0, 300):
pointName = f'MyFactory.Robot_{i}.FaultCode'
robotFaultCode = cimplicity.point_get(pointName)
if robotFaultCode > 0:
OneRobotWithFault = True
break
# Set the status to the variable "WeHaveRobotWithFault"
cimplicity.point_set("WeHaveRobotWithFault", OneRobotWithFault)

MIC-1 Simulation how to get started

Not sure how to start this..
For the given high-level code:
c = b - a;
a = a * 2;
complete the tasks:
create corresponding ijvm hexcode
store into appropriate cells
simulate the instructions
show changing contents of each data cell using "/", using the notation:
< old_value > / < new_value >
Start by writing the equivalent instructions in IJVM. If you are using Tannenbaum's book, there is a simple example for doing a calculation like one of these statements.
Since you have to update the contents of the registers in the data path, IJVM is not sufficient. If you only had to show the contents of the stack, the IJVM would suffice. Tannenbaum has an example of how the stack changes from IJVM instructions.
Once you have the IJVM, look up the opcodes in the instruction table and change operands into offsets from LV.
You will have to take the IJVM instructions and simulate them through MIC-1. Fill in the stack and registers with initial values. Show how the values change as you step through the code, using paper and pen.

Assigning a whole DataStructure its nullind array

Some context before the question.
Imagine file FileA having around 50 fields of different types. Instead of all programs using the file, I tried having a service program, so the file could only be accessed by that service program. The programs calling the service would then receive a DataStructure based on the file structure, as an ExtName. I use SQL to recover the information, so, basically, the procedure would go like this :
Datastructure shared by service program :
D FileADS E DS ExtName(FileA) Qualified
Procedure called by programs :
P getFileADS B Export
D PI N
D PI_IDKey 9B 0 Const
D PO_DS LikeDS(FileADS)
D LocalDS E DS ExtName(FileA) Qualified
D NullInd S 5i 0 Array(50) <-- Since 50 fields in fileA
//Code
Clear LocalDS;
Clear PO_DS;
exec sql
SELECT *
INTO :LocalDS :nullind
FROM FileA
WHERE FileA.ID = :PI_IDKey;
If SqlCod <> 0;
Return *Off;
EndIf;
PO_DS = LocalDS;
Return *On;
P getFileADS E
So, that procedure will return a datastructure filled with a record from FileA if it finds it.
Now my question : Is there any way I can assign the %nullind(field) = *On without specifying EACH 50 fields of my file?
Something like a loop
i = 1;
DoW (i <= 50);
if nullind(i) = -1;
%nullind(datastructure.field) = *On;
endif;
i++;
EndDo;
Cause let's face it, it'd be a pain to look each fields of each file every time.
I know a simple chain(n) could do the trick
chain(n) PI_IDKey FileA FileADS;
but I really was looking to do it with SQL.
Thank you for your advices!
OS Version : 7.1
First, you'll be better off in the long run by eliminating SELECT * and supplying a SELECT list of the 50 field names.
Next, consider these two web pages -- Meaningful Names for Null Indicators and Embedded SQL and null indicators. The first shows an example of assigning names to each null indicator to match the associated field names. It's just a matter of declaring a based DS with names, based on the address of your null indicator array. The second points out how a null indicator array can be larger than needed, so future database changes won't affect results. (Bear in mind that the page shows a null array of 1000 elements, and the memory is actually relatively tiny even at that size. You can declare it smaller if you think it's necessary for some reason.)
You're creating a proc that you'll only write once. It's not worth saving the effort of listing the 50 fields. Maybe if you had many programs using this proc and you had to create the list each time it'd be a slight help to use SELECT *, but even then it's not a great idea.
A matching template DS for the 50 data fields can be defined in the /COPY member that will hold the proc prototype. The template DS will be available in any program that brings the proc prototype in. Any program that needs to call the proc can simply specify LIKEDS referencing the template to define its version in memory. The template DS should probably include the QUALIFIED keyword, and programs would then use their own DS names as the qualifying prefix. The null indicator array can be handled similarly.
However, it's not completely clear what your actual question is. You show an example loop and ask if it'll work, but you don't say if you had a problem with it. It's an array, so a loop can be used much like you show. But it depends on what you're actually trying to accomplish with it.
for old school rpg just include the nulls in the data structure populated with the select statement.
select col1, ifnull(col1), col2, ifnull(col2), etc. into :dsfilewithnull where f.id = :id;
for old school rpg that can't handle nulls remove them with the select statement.
select coalesce(col1,0), coalesce(col2,' '), coalesce(col3, :lowdate) into :dsfile where f.id = :id;
The second method would be easier to use in a legacy environment.
pass the key by value to the procedure so you can use it like a built in function.
One answer to your question would be to make the array part of a data structure, and assign *all'0' to the data structure.
dcl-ds nullIndDs;
nullInd Ind Dim(50);
end-ds;
nullIndDs = *all'0';
The answer by jmarkmurphy is an example of assigning all zeros to an array of indicators. For the example that you show in your question, you can do it this way:
D NullInd S 5i 0 dim(50)
/free
NullInd(*) = 1 ;
Nullind(*) = 0 ;
*inlr = *on ;
return ;
/end-free
That's a complete program that you can compile and test. Run it in debug and stop at the first statement. Display NullInd to see the initial value of its elements. Step through the first statement and display it again to see how the elements changed. Step through the next statement to see how things changed again.
As for "how to do it in SQL", that part doesn't make sense. SQL sets the values automatically when you FETCH a row. Other than that, the array is used by the host language (RPG in this case) to communicate values back to SQL. When a SQL statement runs, it again automatically uses whatever values were set. So, it either is used automatically by SQL for input or output, or is set by your host language statements. There is nothing useful that you can do 'in SQL' with that array.

Matlab: Understanding a piece of code

I have a matlab code which is for printing a cell array to excel. The size of matrix is 50x13.
The row 1 is the column names.
Column 1 is dates and rest columns are numbers.
The dateformat being defined in the code is:
dFormat = struct;
dFormat.Style = struct( 'NumberFormat', '_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(#_)' );
dFormat.Font = struct( 'Size', 8 );
Can someone please explain me what the dFormat.Style code means ?
Thanks
The first line creates an empty struct (struct with no fields) called dFormat. A structure can contain pretty much anything in one of its fields, including another structure. The second line adds a field called 'Style' to the dFormat struct and sets it equal to another struct with a field called 'NumberFormat'. The 'NumberFormat' field is set equal to that long string of characters. You now have a structure of structures. The third line is similar to the second.
Note that the first line isn't really necessary unless dFormat already exists and it needs to be "zeroed out" as dFormat.Style with create it implicitly. However, using the struct function can make code more readable in some cases as objects use a similar notation for access methods and properties. In other words, all of your code could be replaced with:
dFormat.Style.NumberFormat = '_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(#_)';
dFormat.Font.Size = 8;
See this video from the MathWorks for more details and this list of helpful structure functions and examples.
#horchler already elaborated on structs, but I imagine you may actually be more interested in the content of this structs Style field.
In case you are solely interested in _(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(#_), that does not really look like something MATLAB related to me.
My best guess is that this code is used to later feed some other program, for examle to build an excel file.

COBOL add 0 to a Variable in COMPUTE

I ran into a strange statement when working on a COBOL program from $WORK.
We have a paragraph that is opening a cursor (from DB2), and the looping over it until it hits an EOT (in pseudo code):
... working storage ...
01 I PIC S9(9) COMP VALUE ZEROS.
01 WS-SUB PIC S9(4) COMP VALUE 0.
... code area ...
PARA-ONE.
PERFORM OPEN-CURSOR
PERFORM FETCH-CURSOR
PERFORM VARYING I FROM 1 BY 1 UNTIL SQLCODE = DB2EOT
do stuff here...
END-PERFORM
COMPUTE WS-SUB = I + 0
PERFORM CLOSE-CURSOR
... do another loop using WS-SUB ...
I'm wondering why that COMPUTE WS-SUB = I + 0 line is there. My understanding is that I will always at least be 1, because of the perform block above it (i.e., even if there is an EOT to start with, I will be set to one on that initial iteration).
Is that COMPUTE line even needed? Is it doing some implicit casting that I'm not aware of? Why would it be there? Why wouldn't you just MOVE I TO WS-SUB?
Call it stupid, but with some compilers (with the correct options in effect), given
01 SIGNED-NUMBER PIC S99 COMP-5 VALUE -1.
01 UNSIGNED-NUMBER PIC 99 COMP-5.
...
MOVE SIGNED-NUMBER TO UNSIGNED-NUMBER
DISPLAY UNSIGNED-NUMBER
results in: 255. But...
COMPUTE UNSIGNED-NUMBER = SIGNED-NUMBER + ZERO
results in: 1 (unsigned)
So to answer your question, this could be classified as a technique used cast signed numbers into unsigned numbers. However, in the code example you gave it makes no sense at all.
Note that the definition of "I" was (likely) coded by one programmer and of WS-SUB by another (naming is different, VALUE clause is different for same purpose).
Programmer 2 looks like "old school": PIC S9(4), signed and taking up all the digits which "fit" in a half-word. The S9(9) is probably "far over the top" as per range of possible values, but such things concern Programmer 1 not at all.
Probably Programmer 2 had concerns about using an S9(9) COMP for something requiring (perhaps many) fewer than 9999 "things". "I'll be 'efficient' without changing the existing code". It seems to me unlikely that the field was ever defined as unsigned.
A COMP/COMP-4 with nine digits does have a performance penalty when used for calculations. Try "ADD 1" to a 9(9) and a 9(8) and a 9(10) and compare the generated code. If you can have nine digits, define with 9(10), otherwise 9(8), if you need a fullword.
Programmer 2 knows something of this.
The COMPUTE with + 0 is probably deliberate. Why did Programmer 2 use the COMPUTE like that (the original question)?
Now it is going to get complicated.
There are two "types" of "binary" fields on the Mainframe: those which will contain values limited by the PICture clause (USAGE BINARY, COMP and COMP-4); those which contain values limited by the field size (USAGE COMP-5).
With BINARY/COMP/COMP-4, the size of the field is determined from the PICture, and so are the values that can be held. PIC 9(4) is a halfword, with a maxiumum value of 9999. PIC S9(4) a halfword with values -9999 through +9999.
With COMP-5 (Native Binary), the PICture just determines the size of the field, all the bits of the field are relevant for the value of the field. PIC 9(1) to 9(4) define halfwords, pic 9(5) to 9(9) define fullwords, and 9(10) to 9(18) define doublewords. PIC 9(1) can hold a maximum of 65535, S9(1) -32,768 through +32,767.
All well and good. Then there is compiler option TRUNC. This has three options. STD, the default, BIN and OPT.
BIN can be considered to have the most far-reaching affect. BIN makes BINARY/COMP/COMP-4 behave like COMP-5. Everything becomes, in effect, COMP-5. PICtures for binary fields are ignored, except in determining the size of the field (and, curiously, with ON SIZE ERROR, which "errors" when the maxima according to the PICture are exceeded). Native Binary, in IBM Enterprise Cobol, generates, in the main, though not exclusively, the "slowest" code. Truncation is to field size (halfword, fullword, doubleword).
STD, the default, is "standard" truncation. This truncates to "PICture". It is therefore a "decimal" truncation.
OPT is for "performance". With OPT, the compiler truncates in whatever way is the most "performant" for a particular "code sequence". This can mean intermediate values and final values may have "bits set" which are "outside of the range" of the PICture. However, when used as a source, a binary field will always only reflect the value specified by the PICture, even if there are "excess" bits set.
It is important when using OPT that all binary fields "conform to PICture" meaning that code must never rely on bits which are set outside the PICture definition.
Note: Even though OPT has been used, the OPTimizer (OPT(STD) or OPT(FULL)) can still provide further optimisations.
This is all well and good.
However, a "pickle" can readily ensue if you "mix" TRUNC options, or if the binary definition in a CALLing program is not the same as in the CALLed program. The "mix" can occur if modules within the same run-unit are compiled with different TRUNC options, or if a binary field on a file is written with one TRUNC option and later read with another.
Now, I suspect Programmer 2 encountered something like this: Either, with TRUNC(OPT) they noticed "excess bits" in a field and thought there was a need to deal with them, or, through the "mix" of options in a run-unit or "across file usage" they noticed "excess bits" where there would be a need to do something about it (which was to "remove the mix").
Programmer 2 developed the COMPUTE A = B + 0 to "deal" with a particular problem (perceived or actual) and then applied it generally to their work.
This is a "guess", or, better, a "rationalisation" which works with the known information.
It is a "fake" fix. There was either no problem (the normal way that TRUNC(OPT) works) or the correct resolution was "normalisation" of the TRUNC option across modules/file use.
I do not want loads of people now rushing off and putting COMPUTE A = B + 0 in their code. For a start, they don't know why they are doing it. For a continuation it is the wrong thing to do.
Of course, do not just remove the "+ 0" from any of these that you find. If there is a "mix" of TRUNCs, a program may stop "working".
There is one situation in which I have used "ADD ZERO" for a BINARY/COMP/COMP-4. This is in a "Mickey Mouse" program, a program with no purpose but to try something out. Here I've used it as a method to "trick" the optimizer, as otherwise the optimizer could see unchanging values so would generate code to use literal results as all values were known at compile time. (A perhaps "neater" and more flexible way to do this which I picked up from PhilinOxford, is to use ACCEPT for the field). This is not the case, for certain, with the code in question.
I wonder if a testing version of the sources ever had
COMPUTE WS-SUB = I + 0
ON SIZE ERROR
DISPLAY "WS-SUB overflow"
STOP RUN
END-COMPUTE
with the range test discarded when the developer was satisfied and cleaning up? MOVE doesn't allow declarative SIZE statements. That's as much of a reason as I could see. Or perhaps developer habit of using COMPUTE to move, as a subtle reminder to question the need for defensive code at every step? And perhaps not knowing, as Joe pointed out, the SIZE clause would be just as effective without the + 0? Or a maintainer struggled with off by one errors and there was a corrective change from 1 to 0 after testing?