\size normal
-SDCC 2.4.7
+SDCC 2.4.8
\size footnotesize
\newline
/
\end_inset
--nodefaultlibs do not link default libraries when linking.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--obanksel=# Set optimization level for inserting BANKSELs.
-\begin_deeper
-\layout List
-\labelwidthstring 00.00.0000
-
-0 is no optimization
-\layout List
-\labelwidthstring 00.00.0000
-
-1 checks previous used register and if it is the same then does not emit
- BANKSEL, accounts only for labels.
-\layout List
-\labelwidthstring 00.00.0000
-
-2 tries to check the location of (even different) symbols and removes BANKSELs
- if they are in the same bank.
- Important: This will only work properly if the linker script does not have
- sections across bank borders!
-\end_deeper
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--pomit-config-words Omit the generation of the configuration words.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--pomit-ivt Omit the generation of the interrupt vectors.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--pleave-reset-vector Used in conjuction with -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--pomit-ivt, instructs the port NOT to omit the reset vector.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
-stack-model=[model] Used in conjuction with the command above.
Defines the stack model to be used, valid stack models are :
\begin_deeper
/
\end_inset
--call-tree dump call tree in .calltree file
+-mplab-comp MPLAB compatibility option.
+ Currently only suppresses special gpasm directives.
+\layout Subsubsection
+
+Optimization Options
+\layout Standard
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-optimize-goto Try to use (conditional) BRA instead of GOTO
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--mplab-comp MPLAB compatibility option.
- Currently only suppresses special gpasm directives.
+-obanksel=nn Set optimization level for inserting BANKSELs.
+\newline
+
+\begin_deeper
+\layout List
+\labelwidthstring 00.00.0000
+
+0 is no optimization
+\layout List
+\labelwidthstring 00.00.0000
+
+1 checks previous used register and if it is the same then does not emit
+ BANKSEL, accounts only for labels.
+\layout List
+\labelwidthstring 00.00.0000
+
+2 tries to check the location of (even different) symbols and removes BANKSELs
+ if they are in the same bank.
+ Important: This will only work properly if the linker script does not have
+ sections across bank borders!
+\end_deeper
+\layout Subsubsection
+
+Linking Options
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--use-crt= Use a custom run-time module instead of the defaults.
+-nodefaultlibs do not link default libraries when linking
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--no-crt Don't link the default run-time modules
+-use-crt= Use a custom run-time module instead of the defaults.
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--optimize-goto Try to use (conditional) BRA instead of GOTO
+-no-crt Don't link the default run-time modules
\layout Subsubsection
Debugging Options
\end_inset
-gstack Trace push/pops for stack pointer overflow
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-call-tree dump call tree in .calltree file
\layout Subsection
Preprocessor Macros
\layout LyX-Code
void foo(int x);
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
-code place a function symbol at static FLASH address
+The same effect with
+\emph on
+wparam pragma
+\emph default
+ can be achieved with the function attribute
+\emph on
+wparam
+\emph default
+.
+ Usage:
\layout LyX-Code
-Example:
+void func_wparam(int a) wparam
\layout LyX-Code
+{
\layout LyX-Code
-/* place function test_func at 0x4000 */
+...
\layout LyX-Code
-#pragma code test_func 0x4000
+}
+\layout Standard
+
+Limitations of wparam pragma apply for wparam function attribute, too.
\layout List
\labelwidthstring 00.00.0000
-udata pragma udata instructs the compiler to emit code so that linker will
- place a variable at a specific memory bank
+code place a function symbol at static FLASH address
\layout LyX-Code
Example:
\layout LyX-Code
-/* places variable foo at bank2 */
-\layout LyX-Code
-
-#pragma udata bank2 foo
-\layout LyX-Code
-
-char foo;
-\layout Standard
-
-In order for this pragma to work extra SECTION directives should be added
- in the .lkr script.
- In the following example a sample .lkr file is shown:
-\layout LyX-Code
-
-\layout LyX-Code
-
-// Sample linker script for the PIC18F452 processor
-\layout LyX-Code
-
-LIBPATH .
-\layout LyX-Code
-
-CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
-\layout LyX-Code
-
-CODEPAGE NAME=page START=0x2A END=0x7FFF
-\layout LyX-Code
-
-CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
-\layout LyX-Code
-
-CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
-\layout LyX-Code
-
-CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
-\layout LyX-Code
-
-CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
-\layout LyX-Code
-
-ACCESSBANK NAME=accessram START=0x0 END=0x7F
-\layout LyX-Code
-
-\layout LyX-Code
-
-DATABANK NAME=gpr0 START=0x80 END=0xFF
-\layout LyX-Code
-
-DATABANK NAME=gpr1 START=0x100 END=0x1FF
-\layout LyX-Code
-
-DATABANK NAME=gpr2 START=0x200 END=0x2FF
-\layout LyX-Code
-
-DATABANK NAME=gpr3 START=0x300 END=0x3FF
-\layout LyX-Code
-
-DATABANK NAME=gpr4 START=0x400 END=0x4FF
-\layout LyX-Code
-
-DATABANK NAME=gpr5 START=0x500 END=0x5FF
-\layout LyX-Code
-
-ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
-\layout LyX-Code
-
-\layout LyX-Code
-
-SECTION NAME=CONFIG ROM=config
-\layout LyX-Code
-
-\layout LyX-Code
-
-SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
-\layout LyX-Code
-
-SECTION NAME=bank1 RAM=gpr1 # should be added to link
-\layout LyX-Code
-
-SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
-\layout LyX-Code
-
-SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
+/* place function test_func at 0x4000 */
\layout LyX-Code
-SECTION NAME=bank4 RAM=gpr4
+#pragma code test_func 0x4000
\layout LyX-Code
-SECTION NAME=bank5 RAM=gpr5
-\layout Standard
-
-The linker will recognise the section name set in the pragma statement and
- will position the variable at the memory bank set with the RAM field at
- the SECTION line in the linker script file.
\layout List
\labelwidthstring 00.00.0000
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
-\layout Standard
+\layout Standard
+
+
+\series bold
+debug
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+link the debug library
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+libdebug
+\emph default
+.lib
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+* is the device number, i.e.
+ 452 for PIC18F452 MCU.
+\layout Standard
+
+This feature allows for linking with specific libraries withoug having to
+ explicit name them in the command line.
+ Note that the
+\noun on
+ignore
+\noun default
+ keyword will reject all modules specified by the library pragma.
+\layout List
+\labelwidthstring 00.00.0000
+
+udata pragma udata instructs the compiler to emit code so that linker will
+ place a variable at a specific memory bank
+\layout LyX-Code
+
+Example:
+\layout LyX-Code
+
+\layout LyX-Code
+
+/* places variable foo at bank2 */
+\layout LyX-Code
+
+#pragma udata bank2 foo
+\layout LyX-Code
+
+char foo;
+\layout Standard
+
+In order for this pragma to work extra SECTION directives should be added
+ in the .lkr script.
+ In the following example a sample .lkr file is shown:
+\layout LyX-Code
+
+\layout LyX-Code
+
+// Sample linker script for the PIC18F452 processor
+\layout LyX-Code
+
+LIBPATH .
+\layout LyX-Code
+
+CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=page START=0x2A END=0x7FFF
+\layout LyX-Code
+
+CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
+\layout LyX-Code
+
+ACCESSBANK NAME=accessram START=0x0 END=0x7F
+\layout LyX-Code
+
+\layout LyX-Code
+
+DATABANK NAME=gpr0 START=0x80 END=0xFF
+\layout LyX-Code
+
+DATABANK NAME=gpr1 START=0x100 END=0x1FF
+\layout LyX-Code
+
+DATABANK NAME=gpr2 START=0x200 END=0x2FF
+\layout LyX-Code
+
+DATABANK NAME=gpr3 START=0x300 END=0x3FF
+\layout LyX-Code
+DATABANK NAME=gpr4 START=0x400 END=0x4FF
+\layout LyX-Code
-\series bold
-debug
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+DATABANK NAME=gpr5 START=0x500 END=0x5FF
+\layout LyX-Code
-\layout Standard
+ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
+\layout LyX-Code
-link the debug library
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\layout LyX-Code
-\layout Standard
+SECTION NAME=CONFIG ROM=config
+\layout LyX-Code
+\layout LyX-Code
-\emph on
-libdebug
-\emph default
-.lib
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
+\layout LyX-Code
-\end_inset
+SECTION NAME=bank1 RAM=gpr1 # should be added to link
+\layout LyX-Code
+SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
+\layout LyX-Code
-\newline
-* is the device number, i.e.
- 452 for PIC18F452 MCU.
+SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
+\layout LyX-Code
+
+SECTION NAME=bank4 RAM=gpr4
+\layout LyX-Code
+
+SECTION NAME=bank5 RAM=gpr5
\layout Standard
-This feature allows for linking with specific libraries withoug having to
- explicit name them in the command line.
- Note that the
-\noun on
-ignore
-\noun default
- keyword will reject all modules specified by the library pragma.
+The linker will recognise the section name set in the pragma statement and
+ will position the variable at the memory bank set with the RAM field at
+ the SECTION line in the linker script file.
\layout Subsection
Header Files
\layout LyX-Code
su -c 'make install' # install the headers, you need the root password
+\layout Standard
+
+There exist a special target to build the I/O libraries.
+ This target is not automatically build because it will build the I/O library
+ for
+\emph on
+every
+\emph default
+ supported device.
+ This way building will take quite a lot of time.
+ Users are advised to edit the device/lib/pic16/pics.build file and then
+ execute:
\layout LyX-Code
+make lib-io
\layout Subsection
Memory Models
Interrupts
\layout Standard
+An interrupt servive routine (ISR) is declared using the
+\emph on
+interrupt
+\emph default
+ keyword.
+\layout LyX-Code
+
+void isr(void) interrupt
+\emph on
+n
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is the interrupt number, which for PIC18F devices can be:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+n
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector Address
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+RESET vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000000
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+HIGH priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000008
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+LOW priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000018
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+When generating assembly code for ISR the code generator places a
+\noun on
+goto
+\noun default
+instruction at the
+\emph on
+Interrupt Vector Address
+\emph default
+ which points at the genetated ISR.
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is possible to be omitted.
+ This way a function is generated similar to an ISR, but it is not assigned
+ to any interrupt.
+\layout Standard
+
When entering an interrupt, currently the PIC16
\begin_inset LatexCommand \index{PIC16}
\layout Standard
These registers are restored upon return from the interrupt routine.
-
+\layout Subsubsection
+
+Using Shadow Registers
+\layout Standard
+
+When entering/exiting an ISR, it is possible to take advantage of the PIC18F
+ core shadow registers which hold the values of WREG, STATUS and BSR registers.
+ This can be done by adding the keyword
+\emph on
+shadowregs
+\emph default
+ before the
+\emph on
+interrupt
+\emph default
+ keyword in the function's header.
+\layout LyX-Code
+
+void isr_shadow(void) shadowregs interrupt 1
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
\layout Standard
-When entering a high priority interrupt WREG, STATUS and BSR are not explicit
- saved by software.
- The hardware shadow registers for WREG, STATUS and BSR are used in these
- cases.
+
+\emph on
+shadowregs
+\emph default
+ instructs the code generator not to store/restore WREG, STATUS, BSR when
+ entering/exiting the ISR.
\layout Standard
projects / fw / sdcc / blobdiff