diff options
Diffstat (limited to 'notes')
| -rw-r--r-- | notes/coding_standard.txt | 85 | ||||
| -rw-r--r-- | notes/exti.txt | 67 |
2 files changed, 109 insertions, 43 deletions
diff --git a/notes/coding_standard.txt b/notes/coding_standard.txt index 5cb96c3..372ebf4 100644 --- a/notes/coding_standard.txt +++ b/notes/coding_standard.txt @@ -25,12 +25,11 @@ License ------- - Put an MIT license at the beginning of the file (look at any of our - source files for an example). Copyright should go to either you or - LeafLabs LLC. + source files for an example). Copyright should go either to you or + to LeafLabs, LLC. Emacs: if you don't like seeing the license, you should use - elide-head (which will hide it for you). Here is some elisp you can - modify to make this pleasant: + elide-head (which will hide it for you). You can use the following: (require 'elide-head) (setq programming-mode-hooks '(c-mode-hook c++-mode-hook)) @@ -38,7 +37,7 @@ License '("The MIT License" . "DEALINGS IN\n [*] THE SOFTWARE")) (add-to-list 'elide-head-headers-to-hide '("The MIT License" . "DEALINGS IN THE\n...SOFTWARE")) - (dolist (hook mbolivar-programming-mode-hooks) + (dolist (hook programming-mode-hooks) (add-hook hook (lambda () (elide-head)))) Whitespace/Indentation @@ -46,7 +45,8 @@ Whitespace/Indentation - 4 space indents. [Set in .dir-locals.el] -- Unix newlines. +- Unix newlines. [Some exceptions are currently grandfathered in; + these will go away in time.] - No tab characters. [Set in .dir-locals.el] @@ -76,50 +76,53 @@ Whitespace/Indentation (add-hook 'c-mode-hook c-mode-inextern-lang-hook) - Comments -------- -- Multi-line comments look like this: +- Multi-line comments are pretty flexible. Any of these is fine: - /* text starts here - * continued lines have a '*' before them - * the comment can end after the last line + /* Comment starts here. + * Continued lines have a '*' before them. + * The comment can end after the last line. */ - or this: - - /* comment starts here - * the comment can end on the same line */ + /* Comment starts here. + * The comment can end on the same line. */ -- Doxygen comments are newline comments that begin with /** instead. - It is not required that the "/**" appear on a line by itself. + /* + * You can also place a newline after the opening "/*". + */ -- Single-line comments on the same line are // in c or c++. +- Doxygen comments are multi-line comments that begin with /** instead. -- Single-line comments on their own source line are /* */ in c, but - can also be // in c++. If you think that typing out /* */ is too - slow in emacs, use M-; (comment-dwim) when you're on an empty line, - and it'll ... well... +- Single-line comments on the same line are // in C or C++. - You should be using the (super awesome) comment-dwim; it pretty - much does exactly what you want to the comment on the current - line, including "create one and put it in the right place". +- Single-line comments on their own source line should be /* */ in C, + but can also be // in C++. In Emacs, you can use M-; + (comment-dwim), and it'll Do What You Mean. Braces ------ -- 1TBS. Nothing more need be said. +- Mostly 1TBS: http://en.wikipedia.org/wiki/Indent_style#Variant:_1TBS + The only difference is that the opening brace of a function's + definition occurs exactly one space character after the closing + parenthesis in that function's parameter list. Example: + + void func(void) { + ... + } + Naming conventions ------------------ -- There's always a fight about upper and lower case vs. underscores. - We'll handle this as follows. +There's always a fight about upper and lower case vs. underscores. +We'll handle this as follows. - First, Dammit_Dont_Mix_Like_This, because It_Looks_Really_Ugly, ok? +- First, Dammit_Dont_Mix_Like_This, because It_Looks_Really_Ugly, ok? [There's been some debate about this, and some exceptions are already grandfathered in, so in order to settle it, let's call this a "recommendation" instead of "requirement".] @@ -168,7 +171,7 @@ Naming conventions Documentation ------------- -- Document your code. This should go without saying. +- Document your code! - For complicated peripherals, it would be nice if you put longer-form comments into this directory (notes/), with a comment in the @@ -176,13 +179,8 @@ Documentation example. That lets us keep the source files relatively clean while still allowing new readers to have a starting point. -- At least put a doxygen comment with a nonempty @brief for every .h - file you add. See the existing ones for examples. For now, it'd be - better if you didn't put a @brief into any .c[pp] files, since it - (currently) interferes with our documentation generator in a way - that I won't explain here (though you can look into the LeafLabs or - michaeljones breathe repos on github and potentially figure out - why). +- At least put a Doxygen comment with a nonempty @brief for every .h + file you add. See the existing ones for examples. - Doxygen comments generally just belong on types, functions, etc. that are part of the public user-facing API. This generally @@ -196,8 +194,13 @@ Documentation This should be avoided if at all possible, since it creates a maintenance burden of documenting things in two places at once, and - provides an opportunity for bad documentation to slip in, when the - code comments fall out of sync with the ReST docs. + makes it easier for documentation to go stale. + +- For libmaple proper (the pure C library under libmaple/); the + convention is to document any user-facing entity at the point where + it is defined. In particular, this means you should document an + externally-linked function defined in a .c file in that .c file, not + in the header file where it is declared to the user. General Formatting ------------------ @@ -217,7 +220,3 @@ General Formatting (require 'lineker) (dolist (hook '(c-mode-hook c++-mode-hook)) (add-hook hook (lambda () (lineker-mode 1)))) - - There are only a few exceptional situations. The most important one - is when specifying a lookup table like PIN_MAP where it'd be ugly to - split each entry over multiple lines. diff --git a/notes/exti.txt b/notes/exti.txt new file mode 100644 index 0000000..1ad49ee --- /dev/null +++ b/notes/exti.txt @@ -0,0 +1,67 @@ +External interrupt notes. + +To generate the interrupt, the interrupt line should be configured +and enabled. This is done by programming the two trigger registers +with the desired edge detection and by enabling the interrupt +request by writing a '1' to the corresponding bit in the interrupt +mask register. When the selected edge occurs on the external +interrupt line, an interrupt request is generated. The pending bit +corresponding to the interrupt line is also set. This request is +reset by writing a '1' in the pending register. + +Hardware interrupt selection: + +To configure the 20 lines as interrupt sources, use the following +procedure: + +1) Configure AFIO_EXTICR[y] to select the source input for EXTIx + external interrupt +2) Configure the mask bits of the 20 interrupt lines (EXTI_IMR) +3) Configure the trigger selection bits of the interrupt lines + (EXTI_RTSR and EXTI_FTSR) +4) Configure the enable and mask bits that control the NVIC_IRQ + channel mapped to the External Interrupt Controller (EXTI) so + that an inerrupt coming from one of the 20 lines can be + correctly acknowledged. + +AFIO clock must be on. + +RM0008, page 107: "PD0, PD1 cannot be used for external +interrupt/event generation on 36, 48, 64-bin packages." + +---------------------------------------------------------------------------- +Pin to EXTI Line Mappings: +EXTI0 EXTI1 EXTI2 EXTI3 EXTI4 +-------------------------------------------------------------------------- +D2/PA0 D3/PA1 D1/PA2 D0/A6/PA3 D10/A10/PA4 +D26/EXT7/PB0 D27/EXT8/PB1 D16/A2/PC2 D17/A3/PC3 D18/A4/PC4 +D14/A0/PC0 D15/PC1 D25/EXT5/PD2 + +EXTI5 EXTI6 EXTI7 EXTI8 EXTI9 +---------------------------------------------------------------------------- +D13/A13/PA5 D12/A12/PA6 D11/A11/PA7 D6/PA8 D7/PA9 +D4/PB5 D5/PB6 D9/PB7 D38/PB8 D23/EXT4/PB9 +D19/A5/PC5 D34/EXTI15/PC6 D35/EXT16/PC7 D36/PC8 D37/EXT18/PC9 + +EXTI10 EXTI11 EXTI12 EXTI13 EXTI14 +---------------------------------------------------------------------------- +D8/PA10 D29/EXT10/PB11 D30/EXTI1/PB12 D31/EXTI12/PB13 D32/EXT13/PB14 +D28/PB10 D20/EXTI1/PC13 D21/EXT2/PC14 +D25/PC10 + +EXTI15 +---------------------------------------------------------------------------- +D33/EXTI14/PB15 +D22/EXT3/PC15 + + +The 16 EXTI interrupts are mapped to 7 interrupt handlers. + +EXTI Lines to Interrupt Mapping: +EXTI0 -> EXTI0 +EXTI1 -> EXTI1 +EXTI2 -> EXTI2 +EXTI3 -> EXTI3 +EXTI4 -> EXTI4 +EXTI[5-9] -> EXT9_5 +EXTI[10-15] -> EXT15_10 |