Hitex Germany. Application Example. for STR912FW44X. Hitex STR9-comStick / ADC, UART

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1 Hitex Germany Head Quarters Greschbachstr Karlsruhe Germany Fax WEB: Hitex UK Warwick University Science Park Coventry CV47EZ United Kingdom Fax WEB: Hitex USA 2062 Business Center Drive Suite 230 Irvine, CA U.S.A HITEX (US only) Fax WEB: Application Example for STR912F44W Hitex STR9-comStick / ADC, UART This documentation describes the application example and details how to configure and use the ADC peripheral of the STR912F from STMicroelectronics referencing to the ST library functions on the STR9-comStick device. Architecture: ARM9 Device: STR912FW44X Chip Manufacturer: STMicroelectronics Peripherals: ADC, UART1, GPIO, SCU Compiler: GCC Author: Contact: Stefan Grohmann / Hitex Germany applications@hitex.de Revision: 01/ Copyright Hitex Development Tools GmbH All rights reserved. No part of this document may be copied or reproduced in any form or by any means without prior written consent of Hitex Development Tools. Hitex Development Tools retains the right to make changes to these specifications at any time, without notice. Hitex Development Tools makes no commitment to update nor to keep current the information contained in this document. Hitex Development Tools makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hitex Development Tools assumes no responsibility for any errors that may appear in this document. DProbe, Hitex, HiTOP, Tanto, and Tantino are trademarks of Hitex Development Tools. All trademarks of other companies used in this document refer exclusively to the products of these companies. ApplicationExample.dot - 11/

2 Preface In order to support you when working with our products, we provide documents containing specific examples, additional topics, special hints, detailed procedures etc. This document explains features and functions of an application example to run with the HiTOP 5.20 user interface. For more information on the current software and hardware revisions, as well as our update service, please contact or Contents 1 Scope and Disclaimer 3 2 Original Software and Documentation 5 3 Used Modules C Sources Start-Up code and Hardware-Related Modules main.c startup912.s interrupt.c 7 4 Header Files 8 5 Memory Stack 8 6 API Usage 8 7 Customizing STMicroelectronics STR91x Library 9 8 Board Configuration 10 9 Compiler-Specific Keys and Options 10 Copyright 2008 Hitex Development Tools GmbH Page 2/10

3 1 Scope and Disclaimer This software is a simple example to configure and use the AD conversion peripheral and transmit the data with UART. The software relies on the usage of the STMicroelectronics library functions on the STR912F controller from STMicroelectronics. It includes all the initialization and configuration to run the STR912FW44X derivative. Subject Matter The design is made to show the implementation and configuration of the peripherals on the STR9- comstick device board populated with the STR912FW44X controller. Basic functionality of the ADC with the on-board potentiometer device and the UART1 module connected via USB com port is shown. Basic library software is provided by STMicroelectronics for download from The implementation is 'as it is' and no warranties are made. The use and the change of the code is free and not under control of the originators. Requirements Hitex ARM-GNUTool chain GCC for STR9-comStick STR9-comStick device STR912FW44X controller System tool provided by MS-Windows OS or alternative UART connection from the USB port to the STR9-comStick device Hyperterminal software or alternative software Features and Components Platform: STR912FW44X ARM core with ADC and UART peripherals STR9-comStick device hardware GCC ARM9 compilation tools, version UART over USB, ADC with potentiometer peripherals are used Featured STMicroelectronics library for STR9xx is used Copyright 2008 Hitex Development Tools GmbH Page 3/10

4 Procedure Installing 1. Step: Install the Hitex ARM tool chain for STR9-comStick. 2. Step: Plug the STR9-comStick device into a USB port. Starting 1. Step: Copy the project data to the working directory. 2. Step: Copy the library data to the working directory. 3. Step: Load the project "STR9ADC.htp" using the Project > Open command of the HiTOP user interface. 4. Step: Perform a build target using the Project > Build command if object code is not available. 5. Step: Perform a target reset using the Debug > Reset command and run the project with the preconfigured settings. 6. Step: From the Windows Hyperterminal program (see Accessory program group), setup a connection to the USB comport UART with the following settings: Baudrate : bit per second Databits : 8 Parity : none Stopbit : 1 Hardware flow: none Attention! If the project uses the library structures provided with the examples, the library folders must be located in the same directory as the application folders. Otherwise, the project settings must be adapted. Example:..\Work\Application1\Source\ etc. and..\work\library\.. Customizing 1. Step: Adjust the UART settings in the main.c file by changing the entries in the function UART1_Configuration(void) according to your individual needs. 2. Step: Adjust the ADC configuration in the main.c file by changing the entries in the function ADC_Configuration(void) according to your individual needs. 3. Step: Adjust the GPIO configuration in the main.c file by changing the entries in the function GPIO_Configuration(void) according to your individual needs. 4. Step: Adjust the SCU configuration in the main.c file by changing the entries in the function SCU_Configuration(void) according to your individual needs. 5. Step: Adjust the global peripherals configuration in the 91x_conf.h file by changing the comment entries in the file respecting the used peripherals. 6. Step: Recompile the project, download to the target hardware, perform a target reset and run. Copyright 2008 Hitex Development Tools GmbH Page 4/10

5 2 Original Software and Documentation For more information on the STMicroelectronics library functions, see the related documents on The current version and the library to the STR91x hardware offer basic functions of initializing and accessing the elements of the STR91x devices based on the original codes from STMicroelectronics. Other applicational functions can be applied on this basic software. Copyright 2008 Hitex Development Tools GmbH Page 5/10

6 3 Used Modules This chapter describes source files changed or adapted for the ADC-UART demonstration project. For more information on all other files not described here, refer to further application examples and the library description on the WEB pages. 3.1 C Sources All sources are written in pure C following the ANSI rules nearly strictly. For all sources originated by the STMicroelectronics the originator is responsible. Main.c Startup912.s Startup_generic.s interrupt.c 91x_adc.c 91x_fmi.c 91x_gpio.c 91x_scu.c 91x_uart.c 91x_vic.c Main routine invoking the hardware setup and main loop ASM file for initial setup routines ASM file included in Startup912.s Dummy routines for interrupt events Basic library for ADC related functions Basic library for memory and bank management routines Basic library for IO services Basic library for System Control Unit operations Basic library for UART routines Basic library for Vectored interrupt routines Start-Up Code and Hardware-Related Modules For information on the file "Startup912.s", see the related documentation of the start-up code in the Insiders Guide for STR9 from Hitex Development Tools, also available on the STMicroelectronics document WEB page main.c The main program (main.c) provides the following routines: Main() The main routine starts with calls for all related hardware setup routines (SCU, GPIO, ADC and UART). The start-up code in file "Startup912.s" initializes hardware components like PLL, clock and memory. After this first configuration there is no need to change the setup for these elements. However, to show how it can be done the SCU routines are implemented in the file main.c one more time. In an endless loop the ADC flag state is checked until an end of conversion is flagged by the ADC unit. The AD data are captured in the local variable Conversion_Value and the ADC flag is deleted. This causes the ADC unit to perform the next sampling and conversion. The following code line formats a string in character format with the text and the current conversion value. This string is then sent from out of the while loop to the UART. After every UART send command, the state of the UART is checked to ensure no data is lost if the UART is not ready to get the next string element. The following lines perform a general GPIO function by flashing on-board LEDs. Copyright 2008 Hitex Development Tools GmbH Page 6/10

7 SCU_Configuration() Initial configuration of the system control unit. The f MSTR is configured to 96 MHz using the PLL with an external clock source of 25 MHz. The RCLK divider remains to 0 which causes the RCLK to run on f MSTR frequency. PCLK is driven with a divider of 2, relative to the RCLK frequency. The HCLK remains unconfigured. Clock gating for the used peripherals and timers is enabled. GPIO_Configuration() Initial configuration of the GPIO ports including special functions like UART and AD channel. Port 8 drives the LED driver. Port 3 is configured for UART usage. ADC_Configuration() Initial configuration of the AD conversion unit and first conversion start. To perform an analog input capture and conversion, the AD channel 6 is selected with its hardware potentiometer on the STR9- comstick board. The ADC module is configured for continuous mode. UART1_Configuration() Initial configuration of the UART1 peripheral module including sending of a first string. The UART is set to the following parameters: ; 8; N; 1; no hardware flow control FIFO is enabled for send and receive line. Delay(u32 ncount) Counting routine to wait for ncount increments startup912.s One of the main aspects on ARM9 controllers is the usage of appropriate start-up code. The basic initialization of the system clocks, interrupt vectors and memory allocation is done via this file. For further information refer to the Insiders Guide for STR9 from Hitex Development Tools, also available on the STMicroelectronics document WEB page interrupt.c This module contains the specific branches to the interrupt service routines. In this application no interrupts are used. The IRQ routines branched from the VIC module are separately implemented to make the IRQ routine handling easier for the user. Copyright 2008 Hitex Development Tools GmbH Page 7/10

8 4 Header Files Main.h Defines.h 91x_conf.h 91x_map.h 91x_lib.h 91x_scu.h 91x_fmi.h 91x_gpio.h 91x_adc.h 91x_uart.h 91x_vic.h Header file for Main routine General definitions and types Application-specific defines for peripheral units Controller-specific SFR, peripheral access and definitions Application-specific includes and exports according to the headers listed above SCU-related SFRs, data types and function prototypes FMI-related SFRs, data types and function prototypes GPIO-related SFRs, data types and function prototypes ADC-related SFRs, data types and function prototypes UART-related SFRs, data types and function prototypes VIC-related SFRs, data types and function prototypes 5 Memory In general, the amount of RAM on embedded systems is limited and/or they have different timing restrictions if external RAM is used. This application uses the memory defined by the linker file 5.1 Stack The overall size of the reserved stack memory is declared in the "startup912.s" file. The ARM architecture enables to define stack for several processor modes. It is recommended (even for good coding style) to allocate the stack in the appropriate modes. For IRQ, especially when using the VIC unit, stack should be allocated on the IRQ mode section. If the stack is accessed and there is no special routine for checking the processor mode, the stack is treated as a linear memory area with descending addressing. The amount of stack to allocate is strictly depending on the count of expected stack levels and the individual configured stack usage. 6 API Usage The usage of the implemented routines is described in the corresponding library description documents provided by STMicroelectronics. Further documentation is provided on Copyright 2008 Hitex Development Tools GmbH Page 8/10

9 7 Customizing 7.1 STMicroelectronics STR91x Library The STMicroelecronics library has to be configured according to the peripherals used in the application. The configurations and options are described in the related documents on In these documents, the peripheral routines generally used are described. All these options have strong effects on the behavior of the application and should be changed carefully. The options used are the following: Option #define _VIC #define _VIC0 #define _VIC1 #define _FMI #define _GPIO #define GPIO0 #define GPIO1 #define GPIO2 #define GPIO3 #define GPIO4 #define GPIO5 #define GPIO6 #define GPIO7 #define GPIO8 #define GPIO9 #define SCU #define _UART #define _UART0 #define _UART1 #define _UART2 #define _ADC #define _Main_Crystal Comment The VIC unit is not used in this special application. The definition #define _VIC causes the inclusion of the 91_xvic.h file. The fast memory interface must not be configured if the controller works with full speed internal clock of 96 MHz. In general there is always a question of stability and unknown events if the hardware used is not configured and setup correctly. For this reason the FMI module is configured in all application examples. Not all ports are used in this application. The definition #define _GPIO causes the inclusion of the 91x_gpio.h file. The PLL and Clock configuration is set to 96 MHz. This definition causes the inclusion of the 91x_scu.h file. Not all UARTS are used by the current application. Only UART1 is configured. The definition #define _UART causes the inclusion of the 91x_uart.h file. This set of ADC related routines provide an easy access to the ADCs feature. This definition causes the inclusion of the 91x_adc.h file. This entry affects the UART module to calculate the correct settings for the desired baudrate. Copyright 2008 Hitex Development Tools GmbH Page 9/10

10 8 Board Configuration The STR9-comStick device does not have to be configured for use with the HiTOP user interface. 9 Compiler-Specific Keys and Options This chapter describes the compiler-related specific keys and options to handle the code with the ARM-hitex-elf GNU toolchain version compiler/linker. The code generation is configured to produce code for ARM mode. Currently, the libraries are originally written to be used on other compiler platforms. The following options provide standard optimization level (same as the O1 option) and include the libraries in the specified directories (default compiler settings are used): arm-hitex-elf-gcc.exe -mcpu=arm9tdmi -c -gdwarf-2 -MD -Wall -O -mthumb-interwork -mapcs-frame -I.\Source\ -I..\library\inc\ -I..\library\src\ -o.\[objectpath]\[outputname].o..\[sourcepath]\[ sourcename] arm-hitex-elf-as.exe -m armv4t -gdwarf2 -mthumb-interwork -o.\[objectpath]\[outputname].o.\[sourcepath]\[sourcename].s The following settings provide that the linker script file can be portioned for individual needs. Best benefit is the easy way to set up a linker script set once, to include the input.ld file to the project and edit only this file if the file sequence changes. The map file being created is located at the same place as the object files and the elf file. arm-hitex-elf-ld.exe -T.\settings\head.ld -T.\settings\Flash.ld -T.\settings\input.ld -T.\settings\sections.ld --cref -t -static -lc -lgcc -Map=.\Objects\mapfile.map -lm -start-group -o.\objects\outputname.elf -o.\objects\[projectname].elf Copyright 2008 Hitex Development Tools GmbH Page 10/10