STR91X – Library Structure

1. STR91X – Library Structure MCD Application

2. STR91x Software Library Features STR91x Library - All in Strict ANSI-C - Independent from any SW tool chain - Self documented • STR91x Project template • An empty project is provided for each Tool chain • Getting Started document • Start-up files / linker file • STR91x Examples • An example for each STR91x peripheral • Independent from any SW tool chain • Running on STMicroelectronics STR910-Eval board and can be easily tailored to any other hardware

3. Coding conventions • All software is coded in ANSI-C • Strict ANSI-C for all library peripheral files. • PPPis used to reference any peripheral acronym, e.g. TIM for Timer. • Registers & Structures • STR91x registers : • SW library registers have the same names as in STR91x Datasheet & reference manual. • All registers hardware accesses are performed through a C structures : • Work with only one base address and indirect addressing. • Improve code re-use : e.g. the same structure to handle and initialize more Than 4 timers.

4. Common types and constants • Peripheral API code : • Bit fields / Masks • Peripheral user Structure • Low-level & API functions to perform basic operations offered by the peripheral : e.g. :I2C_ReceiveData() • Global headers (includes all) • Peripheral registers’ addresses : • Organized in structures with a base address • Configuration file • Interrupt functions source code • User application source code • Peripherals pointers initialization if #DEBUG defined Application Layer 91x_it.c 91x_lib.h API Layer 91x_it.h Library Structure application.c 91x_conf.h 91x_map.h 91x_type.h 91x_ppp.h 91x_lib.c 91x_ppp.c Hardware Layer PPP

5. Using the Library (1) • Common files (map/lib/type) have to be included to the working directory project • To use the peripheral PPPx • 91x_ppp.c and 91x_ppp.h files must be included to the working project • Edit the 91x_conf.h file and uncomment the following lines : • #define _PPP (mandatory) • #define _PPPx (optional, depending on the peripheral) • If you want to debug your application, you have to define the label DEBUG in the 91x_conf.h file : • #define DEBUG • This creates a pointer, in memory, to the peripheral structure, so debug become easier and dumping a peripheral variable provides all registers settings. • Include this line in your application source code : • #include <91x_lib.h>

6. 91x_conf.h #define DEBUG #define _GPIO /* include gpio.h file */ #define _GPIO0 /* use GPIO0 peripheral */ 91x_map.h typedef volatile struct { u8 DR[1021] ; u16 EMISR; ; u32 DDR; ; u16 EMPTY13;; u16 ISR; u16 AMR; .....; u16 EMPTY14; } GPIO_TypeDef; #define GPIO0_BASE (AHB_APB_BRDG0_U + APB_GPIO0_OFST) #ifdef DEBUG #ifdef _GPIO0 EXT GPIO_TypeDef *GPIO0; #endif /* _GPIO0 */ #else /* NON DEBUG */ #define GPIO0 ((GPIO_TypeDef *)GPIO0_BASE) #endif /* DEBUG */ Using the Library (2) • 91x_lib.h #include "91x_type.h" #include "91x_conf.h" #include "91x_map.h" #ifdef _GPIO #include "91x_gpio.h" #endif To be modified by user Do not modify this file Do not modify this file Define _GPIO in 91x_conf.h to include gpio.h in your project • main.c #include "91x_lib.h" int main { #ifdef DEBUG debug(); #endif /* main program*/ } User file Include 91x_lib.h only Pointers to peripherals structures are used in DEBUG mode Initialize peripheral pointers when in DEBUG mode Constants are used in NON DEBUG mode

7. Using the Library (3) • In the main file , you have to declare a PPP_InitTypeDef structure, e.g: PPP_InitTypeDef PPP_InitStructure; • The PPP_InitStructure is a working variable located in data memory that allows you to initialize one or more instance of PPPs. • You has to fill the PPP_InitStructure variable with the allowed values of the structure member. • Configuration of the whole structure: • PPP_InitStructure.member1 = val1; • PPP_InitStructure.member2 = val2; • ... • PPP_InitStructure.memberN = valN; Note : The previous initialization could be merged in only one line like the following : • PPP_InitTypeDef PPP_InitStructure = { val1, val2, …, valn} • Configuration of few structure’s members: • PPP_StructInit(&PPP_InitStructure); • PPP_InitStructure.memberX = valX; • PPP_InitStructure.memberY = valY;

8. Using the Library (4) • You have to initialize the PPP peripheral by calling the PPP_Init(..) function : • PPP_Init(PPP, &PPP_InitStructure); • At this stage the PPP peripheral is initialized and can be enabled by making a call to PPP_Cmd(..) function. • PPP_Cmd(PPP, ENABLE); • To access the functionality of the PPP peripheral, the user can use a set of dedicated functions. These functions are specific to the peripheral. Notes : 1) For some peripherals the PPP_Cmd(..) function is not implemented (e.g. Peripheral enabled after receiving the Clock). 2) Before configuring a peripheral, you have to make sure that it’s not under Reset and enable its clock by calling the following functions : SCU_APBPeriphClockConfig(__PPP,ENABLE); SCU_APBPeriphReset(__PPP,DISABLE); 3) PPP_DeInit(..) function can be used to set all PPP’s peripheral registers to their reset values: PPP_DeInit(PPP); 4) If after peripheral configuration, the user wants to modify one or more peripheral settings he should proceed as following: PPP_InitStucture.memberX = valX; PPP_InitStructure.memberY = valY; PPP_Init(PPP, &PPP_InitStructure);