1 NOTES file for SDCC pic16 port
4 Current pic16 port status is: Development
6 Some things may change without notification between port updates. The latest
7 CVS snapshot is guarenteed to compile without problems, but does not
8 guarantee backwards compatibility.
10 For any questions please ask the current port
14 Vangelis Rokas <vrokas AT otenet.gr>
16 Other people to contact:
17 Scott Dattalo <scott AT dattalo.com>
19 ======================================================================
20 ======================================================================
21 2004-May-23 Vangelis Rokas
23 1. The improvement of the port has been stalled a bit. But, struct/union
24 SFR headers are ready for the PIC18F[45][45][28] chips along with their
27 2. The genCmp function should be rewritten from scratch.
29 3. The internal helper functions for char/int/long/float arithmetic
30 now compile and will be placed in the appropriate directory under device/
34 2004-Feb-20 Vangelis Rokas
35 Major update with many bugfixes.
37 1. The most of the pic16 regression tests (former pic regression tests) pass
38 successfully. Many thanks to Hans Dorn who did a great job with the
39 arithmetic, shift and pointer functions.
41 2. Bit fields now work properly.
43 3. Stack is permanently enabled. Command argument -pstack-enable is deleted
44 and no more recognized by the port.
47 2004-Feb-07 Vangelis Rokas
49 1. Fixed a bug so that compiler allocated internal registered, will
50 be shared along multiple sources via '.registers' section placed
51 in absolute data memory address 0x0000. Registers 0x00 to 0x7f are
52 considered as internal since they can be used for fast access.
56 2004-Jan-11 Vangelis Rokas
59 The current release of the port can produce object code which is not
60 completely bug free. To use the new features the user should enable them via
61 command line arguments. A sane set of command arguments that I use to test
65 --debug enable sdcc debug information
66 --debug-xtra enable pic16 port debug information (most useful)
67 --debug-ralloc enable register allocator debug messages
68 --pcode-verbose enable verbose pcode generator messages
71 --pno-banksel disable banksel directives for the assembler
72 --pomit-config-words does not emit configuration instruction in
73 the translation This is useful when copmiling
74 multiple sources, when you do not want multiple
75 config instructions in the end file
76 --pomit-ivt disables the dumping of the interrupt vector tables
77 in the translation for the same reasons as above
78 --penable-stack enables stack support. This option uses stack to
79 pass function arguments, and reuses registers between
80 functions by saving the registers used in the function
84 --all-callee-saves you may omit this options as the port
85 enables it by default, all functions are currently
86 compiled as reentrant and they are marked as
88 --no-peep peephole optimizer is better to be switched off,
89 because it behaves strangely in some cases
90 --fommit-frame-pointer this omits frame pointer in functions that
91 don't use registers (maybe changed later, not
96 The current implementation puts every function in its own code section in
97 PIC's program memory. This may not be the standard, but I think its more
101 Since SDCC is goind for a release, its better to document pragmas available.
104 The 'code' pragma emits a function's code at a specific address in program
105 memory. Currently it is only used for functions.
107 #pragma code [function_name] [address]
110 The 'stack' pragma initializes the stack/frame pointer at an address of the
111 data ram other than the default (which is the end of the available data ram)
113 #pragma stack [address]
116 The 'maxram' pragma sets maximum data ram of the device. Currently is not
117 used at all, but it may be useful in the future when devices with external
118 memory will be supported.
120 #pragma maxram [max_address]
123 4. Internal compiler functions
124 Internal SDCC functions like, __fsmul, etc... are currently supported by the
125 port, but the libraries for the pic16 port are not yet ready. So one cannot
126 use long and float variables.
129 5. Special Function Registers (SFRs)
130 The processor SFRs are not anymore declared in any header file. The user can
131 define by himself all the needed SFR's. The code to that is:
133 sfr at [sfr_address] [sfr_name];
135 Where sfr_address is the SFR address in the data ram, and sfr_name is the
136 name of the SFR. i.e.: