HPDPIC

INDEX
Chip types
Compiler optimizations
Editor Searching
External ROM addresses
Floating point sizes
String search
User defined commands

Chip types

Use this dialog to select the target PIC processor you will be using. Setting the chip type will determine the ROM and RAM available to the compiler, as well as defining a pre-processor variable to allow testing the chip type, e.g. selecting 16C84 will set the preprocessor macro _16C84 - this is also used in to choose the appropriate register definitions.

Compiler optimizations

An "optimization" is a transformation performed by the compiler on a program to make it smaller and/or faster.

The compiler performs many optimizations, some automatically, some only when requested. The Optimization dialog box allows selection of optimizations to be performed when compiling:

Global:	Global optimization is performed one function at a time and aims to optimize the use of registers within whole functions. When used, this allocates variables to registers based on analysis of which variables will benefit most. This optimization can be quite time consuming on large functions. It is possible for the code generator to run out of memory when performing global optimization. The function size should be reduced if this occurs.
Peephole:	Peephole optimization is a process of examining generated assembler code and "improving" it. This includes redundant load/store optimization, branch optimization, and substitution of faster or shorter instructions. Whole functions are optimized at a time, and it is possible for the optimizer to run out of memory on large functions.
Assembler:	The assembler attempts to turn long branches or jumps into short branches when this is used. This does not use extra memory, but can increase the compile time.

Editor Searching

The editor allows search and search/replace forwards or backwards, using either simple strings, or "regular expressions". The search/replace dialog can be accessed via several paths:

  1.   by using the WordStar style commands Ctrl-Q A and Ctrl-Q F.
  2.   by clicking the "Search" button in the editor window.
  3.   by pressing F2 in the editor window.
  4.   by the "Search ..." or "Replace ..." items in the "Edit" menu.

The search/replace dialog allows both search and replace operations to be selected, starting from any of the search/replace commands. The settings in the dialog will default to appropriate values based on the previous operation and the method used to activate the dialog. Selection between search and replace operations is performed using the "Replace - F3" check box. If performing a replace operation, the check box "Global - F5" allows an interactive global search/replace to be performed. The "Replace all - F6" check box allows all instances of the search string to be replaced without asking. You can select between case sensitive and case insensitive searching using the "Case sensitive - F4" check box. In addition to the search/replace commands which display the dialog, the editor also allows the previous search/replace operation to be repeated in either a forward or backward direction. This can be achieved using the following key or mouse strokes:

Search for NEXT:	Ctrl-L or Shift-F2 or click the NEXT button.
Search for PREVIOUS:	Ctrl-L or Ctrl-F2 or click the PREV button.

REGULAR EXPRESSION MATCHING

Regular expressions are a generalization of "wild card" matching. A regular expression can include literal text (e.g. "abcdef") or various special characters that are interepreted specially when comparing the search string with the text in the editor. In brief, the special characters are:

^	Match start of line
$	Match end of line
?	Match any character
*	Repeat previous expression
	Group a sequence
[ ]	Specify a range or set of characters to match
\	Escape a special character

In more detail:

^	Use at the beginning of a search string to anchor the search to the beginning of the line, e.g. ^#define will match #define only if it is at the beginning of a line.
$	Matches the end of a line, e.g. 0);$ will match "0);" only at the end of a line.
?	matches any character, e.g. ??xyz? would match any of: "12xyzb", "..xyz1" or "AAxyzA"
*	means any number of repetitions of the previous regular expression. The previous regular expression is either a single character, or a parenthesized expression or range as below. For example: ab* will match the letter 'a' followed by zero or more letters 'b'.
	These two character pairs enclose a regular expression that can be the subject of the * repetition character, e.g ab$ab$* will match one or more sequences of "ab", e.g. "ababab". Note that the first "ab" must be matched with "ab", and the sequence inside the parentheses can match zero or more sequences of "ab".
[ ]	These brackets are used to enclose a character range or set. Within the brackets can be any number of single characters, or pairs of characters separated by a dash. For example: [ABCDEF0-9] will match any upper case alphabetic from A to F, or any digit. If it is desired to include a dash in the set, make it the first or last character. Similarly, the right bracket (]) must be first if it is to be part of the set. For example: []a-f-] will match any lower case alphabetic, ] or -.
\	Escape any special character. Precede any of ?, , $, ^ or [ to force them to be treated literally. For example: \\** will match one or more asterisks in sequence.

External ROM addresses

The 17Cxx series PICMicro devices can address external memory in certain modes. This dialog box allows you to specify the ranges of external addresses that access external ROM memory. This memory will be used for program code and constant data. Each range should be specified in hex as a starting address and an ending address, e.g. 4000 to 4FFF represents 4096 words of memory. NOTE: these ranges should not overlap the on-chip ROM.

Floating point sizes

The compiler will generate code by default for floating point operations using 24 bits (8 bit exponent, 16 bit mantissa). This will apply to both 'float' and 'double' values. Selecting the "32 bit double" option will mean any 'double' values will be evaluated in 32 bits (8 bit exponent, 24 bit mantissa). This will also affect library routines like sin() that operate on and return double results.

When using 32-bit doubles, libraries with faster multiply and divide routines can be used to speed up floating point maths. An increase in code and data size will result when using these libraries.

String search

The string search dialog is used to access a "grep" like utility which will perform a search of one or more files for a specified target string. The search string may consist of any sequence of characters, including spaces. The default behaviour is to perform a case insensitive search where lower case and upper case characters are treated as equivalent. If the "Case sensitive - F4" check box is selected, a case sensitive search may be performed.

The list of files to search may be specified either by typing a list of wildcards in the "File list:" edit line, or by selecting the check box: "Current project - F6". The file list entered may consist of one or more file names or wildcards. If the same file is selected by more than one wildcard, the file will only be searched once. If "Current project" is selected, all source files in the current HPD project will be searched for the target string. If you wish to search a user specified file list, select the "File list - F5" check box.

The results of the search will be displayed in the "String search:" window. You may move between entries in this window using the mouse, window scroll bar, or the arrow/cursor keys on the keypad. To select a search result, double click the mouse in its entry, or press enter when the desired line is highlighted. When a selection is made, the selected file will be loaded into the HPD editor with the cursor and search highlight positioned on the selected text.

The "Search F2" button in the "String search:" window may be used to search again without using the menu.

User defined commands

The "User command setup" dialog allows four user defined external commands to be added to the Utility menu. Each user defined command entry consists of two strings; the menu entry which will be displayed in the Utility menu, and the command line which will be executed by DOS when the menu item is selected. Typically the user commands will be used to interface to external debuggers and editors.

A number of macros may be used within user defined commands to allow substitution of useful filenames. The available macros are:

$(EDIT)	Current HPD edit file
$(OUTFILE)	Current output file name
$(CWD)	Current working directory
$(LIB)	Compiler LIB directory path
$(INC)	Compiler INCLUDE directory path
$(PROJ)	Name of current project file

For example, a user defined command which passes the current HPD edit file to an external editor called EDIT would be:

EDIT $(EDIT)

Converted to HTML by Philippe Corbes (Email:philippe.corbes@laposte.net) 11/11/2002.