TEXAS INSTRUMENTS 2802x Technical data

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2802x C/C++ Header Files and Peripheral Examples Quick Start

Version 1.25

December 18, 2009

SPRC992

2802x C/C++ Header Files and Peripheral Examples

Quick Start

1 Device Support:............................................................................................................................ 2

2 Introduction: ................................................................................................................................. 2

2.1 Revision History...................................................................................................................... 3

2.2 Where Files are Located (Directory Structure) ........................................................................ 4

3 Understanding The Peripheral Bit-Field Structure Approach ................................................... 6

4 Peripheral Example Projects ....................................................................................................... 7

4.1 Getting Started ....................................................................................................................... 7

4.1.1 Getting Started in Code Composer Studio v4.0+......................................................... 7

4.2 Example Program Structure.................................................................................................. 13

4.2.1 Source Code............................................................................................................. 14

4.2.2 Linker Command Files .............................................................................................. 14

4.3 Example Program Flow......................................................................................................... 16

4.4 Included Examples: .............................................................................................................. 17

4.5 Executing the Examples From Flash..................................................................................... 19

5 Steps for Incorporating the Header Files and Sample Code ................................................... 23

5.1 Before you begin................................................................................................................... 23

5.2 Including the DSP2802x Peripheral Header Files ................................................................. 23

5.3 Including Common Example Code........................................................................................ 27

6 Troubleshooting Tips & Frequently Asked Questions............................................................. 30

6.1 Effects of read-modify-write instructions. .............................................................................. 32

6.1.1 Registers with multiple flag bits in which writing a 1 clears that flag........................... 33

6.1.2 Registers with Volatile Bits........................................................................................ 33

7 Migration Tips for moving from the TMS320x280x or TMS320x281x header files to the

TMS320x2802x header files ....................................................................................................... 34

8 Packet Contents:........................................................................................................................ 35

8.1 Header File Support – DSP2802x_headers.......................................................................... 35

8.1.1 DSP2802x Header Files – Main Files........................................................................ 35

8.1.2 DSP2802x Header Files – Peripheral Bit-Field and Register Structure Definition

Files .......................................................................................................................... 36

8.1.3 Variable Names and Data Sections........................................................................... 37

8.2 Common Example Code – DSP2802x_common................................................................... 38

8.2.1 Peripheral Interrupt Expansion (PIE) Block Support .................................................. 38

8.2.2 Peripheral Specific Files............................................................................................ 39

8.2.3 Utility Function Source Files...................................................................................... 40

8.2.4 Example Linker .cmd files ......................................................................................... 40

8.2.5 Example Library .lib Files .......................................................................................... 41

9 Detailed Revision History: ......................................................................................................... 42

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1 Device Support:

This software package supports 2802x devices. This includes the following: TMS320F28027, TMS320F28026, TMS320F28023, TMS320F28022, TMS320F28021, TMS320F28020, and TMS320F280200.

Throughout this document, TMS320F28027, TMS320F28026, TMS320F28023, TMS320F28022, TMS320F28021, TMS320F28020, and TMS320F280200 are abbreviated as F28027, F28026, F28023, F28022, F28021, F28020, and F280200 respectively.

2 Introduction:

The 2802x C/C++ peripheral header files and example projects facilitate writing in C/C++ Code for the Texas Instruments TMS320x2802x DSPs. The code can be used as a learning tool or as the basis for a development platform depending on the current needs of the user.

• Learning Tool:

This download includes several example Code Composer Studio™† v4.0+ projects for a ‘2802x development platform.

These examples demonstrate the steps required to initialize the device and utilize the onchip peripherals. The provided examples can be copied and modified giving the user a platform to quickly experiment with different peripheral configurations.

These projects can also be migrated to other devices by simply changing the memory allocation in the linker command file.

• Development Platform:

The peripheral header files can easily be incorporated into a new or existing project to provide a platform for accessing the on-chip peripherals using C or C++ code. In addition, the user can pick and choose functions from the provided code samples as needed and discard the rest.

To get started this document provides the following information:

• Overview of the bit-field structure approach used in the 2802x C/C++ peripheral header files.

• Overview of the included peripheral example projects.

• Steps for integrating the peripheral header files into a new or existing project.

• Troubleshooting tips and frequently asked questions.

• Migration tips for users moving from the DSP280x header files to the DSP2802x header

files.

†

Code Composer Studio is a trademark of Texas Instruments (www.ti.com).

Finally, this document does not provide a tutorial on writing C code, using Code Composer Studio, or the C28x Compiler and Assembler. It is assumed that the reader already has a 2802x hardware platform setup and connected to a host with Code Composer Studio installed. The user should have a basic understanding of how to use Code Composer Studio to download code through JTAG and perform basic debug operations.

2.1 Revision History

Version 1.25

 This version includes minor corrections to the header files and examples. The most

notable change is that gel files and cmd linker files for the 280200 devices now include 1K additional L0 RAM. A detailed revision history can be found in Section 9.

Version 1.21b

 This version update only updates the V1.21 Quick Start Readme to adjust wording for

the controlSUITE software package. No changes to the header file and peripheral example code were made.

Version 1.21

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 This version includes minor corrections and comment fixes to the header files and

examples. A detailed revision history can be found in Section 9.

Version 1.20

 This version includes corrections and comment fixes to the header files and examples.

It adds examples pertaining to the ADC temperature sensor and compensation of the oscillator frequency over temperature, and it also fixes an error in the SFO_TI_Build_V6.lib library in the new SFO_TI_Build_V6b.lib library . A detailed revision history can be found in Section 9.

Version 1.10

 This version includes corrections and comment fixes to the header files and examples,

adds 3 new 2802x devices – 28021, 28020, and 280200 - , deletes 2 2802x devices – 28024 and 28025 - and also adds a separate example folder, DSP2802x_examples_ccsv4, with examples supported by the Eclipse-based Code Composer Studio v4. A detailed revision history can be found in Section 9.

Version 1.00

 This version is the first release of the 2802x header files and examples.

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2.2 Where Files are Located (Directory Structure)

As installed, the 2802x C/C++ Header Files and Peripheral Examples is partitioned into a well-defined directory

structure.

Table 1 describes the contents of the main directories used by DSP2802x header files and peripheral examples:

Table 1. DSP2802x Main Directory Structure

Directory Description

<base> Base install directory. For the rest of this document <base> will be omitted

from the directory names. <base>\doc Documentation including the revision history from the previous release. <base>\DSP2802x_headers Files required to incorporate the peripheral header files into a project .

The header files use the bit-field structure approach described in Section

Integrating the header files into a new or existing project is described in

Section 5. <base>\DSP2802x_examples_ccsv4 Example Code Composer Studio v4.0+ projects. These example projects

illustrate how to configure many of the on-chip peripherals. An overview of

the examples is given in Section 4. <base>DSP2802x_common Common source files shared across example projects to illustrate how to

perform tasks using header file approach. Use of these files is optional,

but may be useful in new projects. A list of these files is in Section 8.

Under the DSP2802x_headers and DSP2802x_common directories the source files are further broken down into sub-directories each indicating the type of file. Table 2 lists the sub-

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directories and describes the types of files found within each:

Table 2. DSP2802x Sub-Directory Structure

Sub-Directory Description

DSP2802x_headers\cmd Linker command files that allocate the bit-field structures described in Section 3. DSP2802x_headers\source Source files required to incorporate the header files into a new or existing

project.

DSP2802x_headers\include Header files for each of the on-chip peripherals.

DSP2802x_common\cmd Example memory command files that allocate memory on the devices. DSP2802x_common\include Common .h files that are used by the peripheral examples. DSP2802x_common\source Common .c files that are used by the peripheral examples. DSP2802x_common\lib Common library (.lib) files that are used by the peripheral examples. DSP2802x_common\gel\ccsv4 Code Composer Studio v4.x GEL files for each device. These are optional.

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3 Understanding The Peripheral Bit-Field Structure Approach

The following application note includes useful information regarding the bit-field peripheral structure approach used by the header files and examples.

This method is compared to traditional #define macros and topics of code efficiency and special case registers are also addressed. The information in this application note is important to understand the impact using bit fields can have on your application code.

Programming TMS320x28xx and 28xxx Peripherals in C/C++ (SPRAA85)

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4 Peripheral Example Projects

This section describes how to get started with and configure the peripheral examples included in the 2802x Header Files and Peripheral Examples software package.

4.1 Getting Started

4.1.1 Getting Started in Code Composer Studio v4.0+

To get started, follow these steps to load the 32-bit CPU-Timer example. Other examples are set-up in a similar manner.

1. Have a hardware platform connected to a host with Code Composer Studio installed.

NOTE: As supplied, the ‘2802x example projects are built for the ‘28027 device. If you

are using another 2802x device, the memory definition in the linker command file (.cmd) will need to be changed and the project rebuilt.

2. Open the example project.

Each example has its own project directory which is “imported”/opened in Code Composer Studio v4.

To open the ‘2802x CPU-Timer example project directory, follow the following steps:

a. In Code Composer Studio v 4.x: Project->Import Existing CCS/CCE Eclipse Project.

b. Next to “Select Root Directory”, browse to the CPU Timer example directory:

DSP2802x_examples_ccsv4\cpu_timer. Select the Finish button.

This will import/open the project in the CCStudio v4 C/C++ Perspective project window.

3. Edit DSP28_Device.h

Edit the DSP2802x_Device.h file and make sure the appropriate device/package combination is selected. By default the 28027 PT package is selected.

/******************************************************************** * DSP2802x_headers\include\DSP2802x_Device.h ********************************************************************/

#define TARGET 1 //--------------------------------------------------------------------------// User To Select Target Device:

define DSP28_280200PT 0 #define DSP28_280200DA 0

#define DSP28_28020PT 0 #define DSP28_28020DA 0

#define DSP28_28021PT 0 #define DSP28_28021DA 0

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#define DSP28_28022PT 0 #define DSP28_28022DA 0

#define DSP28_28023PT 0 #define DSP28_28023DA 0

#define DSP28_28026PT 0 #define DSP28_28026DA 0

#define DSP28_28027PT TARGET #define DSP28_28027DA 0

4. Edit DSP2802x_Examples.h

Edit DSP2802x_Examples.h and specify the clock rate, the PLL control register value (PLLCR and DIVSEL). These values will be used by the examples to initialize the PLLCR register and DIVSEL bits.

The default values will result in a 60Mhz SYSCLKOUT frequency.

/******************************************************************** * DSP2802x_common\include\DSP2802x_Examples.h ********************************************************************/ /*---------------------------------------------------------------------------- Specify the PLL control register (PLLCR) and divide select (DIVSEL) value.

-----------------------------------------------------------------------------*/ //#define DSP28_DIVSEL 0 // Enable /4 for SYSCLKOUT(default at reset) //#define DSP28_DIVSEL 1 // Disable /4 for SYSCKOUT #define DSP28_DIVSEL 2 // Enable /2 for SYSCLKOUT //#define DSP28_DIVSEL 3 // Enable /1 for SYSCLKOUT

#define DSP28_PLLCR 12 //#define DSP28_PLLCR 11 //#define DSP28_PLLCR 10 //#define DSP28_PLLCR 9 //#define DSP28_PLLCR 8 //#define DSP28_PLLCR 7 //#define DSP28_PLLCR 6 //#define DSP28_PLLCR 5 //#define DSP28_PLLCR 4 //#define DSP28_PLLCR 3 //#define DSP28_PLLCR 2 //#define DSP28_PLLCR 1 //#define DSP28_PLLCR 0 // (Default at reset) PLL is bypassed in this mode //----------------------------------------------------------------------------

In DSP2802x_Examples.h, also specify the SYSCLKOUT rate. This value is used to scale a delay loop used by the examples. The default value is for a 60 Mhz SYSCLKOUT. If you have a 50 Mhz device or a 40 MHz device you will need to adjust these settings accordingly.

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/******************************************************************** * DSP2802x_common\include\DSP2802x_Examples.h ********************************************************************/ …… #define CPU_RATE 16.667L // for a 60MHz CPU clock speed (SYSCLKOUT) //#define CPU_RATE 20.000L // for a 50MHz CPU clock speed (SYSCLKOUT) //#define CPU_RATE 25.000L // for a 40MHz CPU clock speed (SYSCLKOUT) //#define CPU_RATE 33.333L // for a 30MHz CPU clock speed (SYSCLKOUT) ……

In DSP2802x_Examples.h the target device chosen in DSP2802x_Device.h also specifies the maximum SYSCLKOUT frequency (60 MHz, 50 Mhz, or 40 MHz) by setting it to 1 and the other to 0 via compiler directives. This value is used by those examples with timing dependent code (i.e. baud rates or other timing parameters) to determine whether 60MHz code, 50 Mhz code, or 40MHz code should be run.

The default value is for 60Mhz SYSCLKOUT for the ‘28027 device. If you have selected a 50 Mhz device or a 40 MHz device in DSP2802x_Device.h, the frequency settings are adjusted accordingly. If you intend to run examples which use these definitions at a different frequency, then the timing parameters in those examples must be directly modified accordingly regardless of the setting here.

/******************************************************************** * DSP2802x_common\include\DSP2802x_Examples.h ********************************************************************/ …… #if (DSP28_28026PT||DSP28_28026DA||DSP28_28027PT||DSP28_28027DA) // 28026||28027 devices only #define CPU_FRQ_60MHZ 1 // 60 Mhz CPU Freq (10 MHz input clock) #define CPU_FRQ_50MHZ 0 #define CPU_FRQ_40MHZ 0 #elif (DSP28_28023PT||DSP28_28023DA||DSP28_28022PT||DSP28_28022DA) // 28023||28023 devices #define CPU_FRQ_60MHZ 0 #define CPU_FRQ_50MHZ 1 // 50 MHz CPU Freq (10 MHz input clock) #define CPU_FRQ_40MHZ 0 #else // 28021||28020||280200 devices #define CPU_FRQ_60MHZ 0 #define CPU_FRQ_50MHZ 0 #define CPU_FRQ_40MHZ 1 // 40 MHz CPU Freq (10 MHz input clock) #endif//----------------------------------------------------------------------------

5. Review the comments at the top of the main source file: Example_2802xCpuTimer.c.

A brief description of the example and any assumptions that are made and any external hardware requirements are listed in the comments at the top of the main source file of each example. In some cases you may be required to make external connections for the example to work properly.

6. Perform any hardware setup required by the example.

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Perform any hardware setup indicated by the comments in the main source. The CPUTimer example only requires that the hardware be setup for “Boot to SARAM” mode. Other examples may require additional hardware configuration such as connecting pins together or pulling a pin high or low.

Table 3 shows a listing of the boot mode pin settings for your reference. Table 4 and Table 5 list the EMU boot modes (when emulator is connected) and the Get Mode boot mode options (mode is programmed into OTP) respectively. Refer to the documentation for your hardware platform for information on configuring the boot mode pins. For more information on the ‘2802x boot modes refer to the device specific Boot ROM Reference Guide.

Table 3. 2802x Boot Mode Settings

GPIO37

TDO

X X 1 EMU Mode 0 0 0 Parallel I/O 0 1 0 SCI 1 0 0 Wait 1 1 0 “Get Mode”

GPIO34

CMP2OUT

TRSTn

Mode

Table 4. 2802x EMU Boot Modes (Emulator Connected)

EMU_KEY

0x0D00

!= 0x55AA x Wait

0x55AA

EMU_BMODE

0x0D01

0x0000 Parallel I/O

0x0001 SCI 0x0002 Wait 0x0003 Get Mode 0x0004 SPI 0x0005 I2C 0x0006 OTP 0x0007 Wait

0x0008 Wait 0x000A Boot to RAM 0x000B Boot to FLASH

Other Wait

Boot Mode Selected

Table 5. 2802x GET Boot Modes (Emulator Disconnected)

OTP_KEY OTP_BMODE Boot Mode Selected

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0x3D7BFE 0x3D7BFF

!= 0x55AA x Get Mode - Flash

0x55AA

When the emulator is connected for debugging:

TRSTn = 1, and therefore the device is in EMU boot mode. In this situation, the user must write the key value of 0x55AA to EMU_KEY at address 0x0D00 and the desired EMU boot mode value to EMU_BMODE at 0x0D01 via the debugger window according to Table 4. The 2802x gel files in the DSP2802x_common/gel/ directory have a GEL function – EMU Boot Mode Select -> EMU_BOOT_SARAM() which performs the debugger write to boot to “SARAM” mode when called.

When the emulator is not connected for debugging:

0x0001 Get Mode - SCI 0x0003 Get Mode – Flash 0x0004 Get Mode - SPI 0x0005 Get Mode - I2C 0x0006 Get Mode - OTP

Other Get Mode - Flash

SCI or Parallel I/O boot mode can be selected directly via the GPIO pins, or OTP_KEY at address 0x3D7BFE and OTP_BMODE at address 0x3D7BFF can be programmed for the desired boot mode per Table 5.

7. Build and Load the code

Once any hardware configuration has been completed, in Code Composer Studio v4, go to Target->Debug Active Project.

This will open the “Debug Perspective” in CCSv4, build the project, load the .out file into the 28x device, reset the part, and execute code to the start of the main function. By default, in Code Composer Studio v4, every time Debug Active Project is selected, the code is automatically built and the .out file loaded into the 28x device.

8. Run the example, add variables to the watch window or examine the memory contents.

At the top of the code in the comments section, there should be a list of “Watch variables”. To add these to the watch window, highlight them and right-click. Then select Add Watch expression. Now variables of interest are added to the watch window.

9. Experiment, modify, re-build the example.

If you wish to modify the examples it is suggested that you make a copy of the entire header file packet to modify or at least create a backup of the original files first. New examples provided by TI will assume that the base files are as supplied.

Sections 4.2 and 4.3 describe the structure and flow of the examples in more detail.

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10. When done, delete the project from the Code Composer Studio v4 workspace.

Go to View->C/C++ Projects to open up your project view. To remove/delete the project from the workspace, right click on the project’s name and select delete. Make sure the Do not delete contents button is selected, then select Yes. This does not delete the project itself. It merely removes the project from the workspace until you wish to open/import it again.

The examples use the header files in the DSP2802x_headers directory and shared source in the DSP2802x_common directory. Only example files specific to a particular example are located within in the example directory.

Note: Most of the example code included uses the .bit field structures to access registers. This is done to help the user learn how to use the peripheral and device. Using the bit fields has the advantage of yielding code that is easier to read and modify. This method will result in a slight code overhead when compared to using the .all method. In addition, the example projects have the compiler optimizer turned off. The user can change the compiler settings to turn on the optimizer if desired.

4.2 Example Program Structure

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Each of the example programs has a very similar structure. This structure includes unique source code, shared source code, header files and linker command files.

/******************************************************************** * DSP2802x_examples_ccsv4\cpu_timer\Example_2802xCpuTimer.c ********************************************************************/

#include "DSP28x_Project.h" // Device Headerfile and Examples Include File

• DSP28x_Project.h

This header file includes DSP2802x_Device.h and DSP2802x_Examples.h. Because the name is device-generic, example/custom projects can be easily ported between different device header files. This file is found in the <base>\DSP2802x_common\include directory.

• DSP2802x_Device.h

This header file is required to use the header files. This file includes all of the required peripheral specific header files and includes device specific macros and typedef statements. This file is found in the <base>\DSP2802x_headers\include directory.

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• DSP2802x_Examples.h

This header file defines parameters that are used by the example code. This file is not required to use just the DSP2802x peripheral header files but is required by some of the common source files. This file is found in the <base>\DSP2802x_common\include directory.

4.2.1 Source Code

Each of the example projects consists of source code that is unique to the example as well as source code that is common or shared across examples.

• DSP2802x_GlobalVariableDefs.c

Any project that uses the DSP2802x peripheral header files must include this source file. In this file are the declarations for the peripheral register structure variables and data section assignments. This file is found in the <base>\DSP2802x_headers\source directory.

• Example specific source code:

Files that are specific to a particular example have the prefix Example_2802x in their filename. For example Example_2802xCpuTimer.c is specific to the CPU Timer example and not used for any other example. Example specific files are located in the <base>\DSP2802x_examples_ccsv4\<example> directory.

• Common source code:

The remaining source files are shared across the examples. These files contain common functions for peripherals or useful utility functions that may be re-used. Shared source files are located in the DSP2802x_common\source directory. Users may choose to incorporate none, some, or the entire shared source into their own new or existing projects.

4.2.2 Linker Command Files

Each example uses two linker command files. These files specify the memory where the linker will place code and data sections. One linker file is used for assigning compiler generated sections to the memory blocks on the device while the other is used to assign the data sections of the peripheral register structures used by the DSP2802x peripheral header files.

• Memory block linker allocation:

The linker files shown in 0 are used to assign sections to memory blocks on the device. These linker files are located in the <base>\DSP2802x_common\cmd directory. Each example will use one of the following files depending on the memory used by the example.

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Table 6. Included Memory Linker Command Files

Memory Linker Command

File Examples

28027_RAM_lnk.cmd DSP2802x_common\cmd 28027 memory linker command file.

28026_RAM_lnk.cmd DSP2802x_common\cmd 28026 SARAM memory linker command

28023_RAM_lnk.cmd DSP2802x_common\cmd 28023 SARAM memory linker command

28022_RAM_lnk.cmd DSP2802x_common\cmd 28022 SARAM memory linker command

28021_RAM_lnk.cmd DSP2802x_common\cmd 28021 SARAM memory linker command

28020_RAM_lnk.cmd DSP2802x_common\cmd 28020 SARAM memory linker command

280200_RAM_lnk.cmd DSP2802x_common\cmd 280200 SARAM memory linker command

F28027.cmd DSP2802x_common\cmd F28027 memory linker command file.

F28026.cmd DSP2802x_common\cmd F28026 memory linker command file. F28023.cmd DSP2802x_common\cmd F28023 memory linker command file. F28022.cmd DSP2802x_common\cmd F28022 memory linker command file. F28021.cmd DSP2802x_common\cmd F28021 memory linker command file. F28020.cmd DSP2802x_common\cmd F28020 memory linker command file. F280200.cmd DSP2802x_common\cmd F280200 memory linker command file.

Location Description

Includes all of the internal SARAM blocks on 28027 device. “RAM” linker files do not include flash or OTP blocks.

file.

Includes all Flash, OTP and CSM password protected memory locations.

• Header file structure data section allocation:

Any project that uses the header file peripheral structures must include a linker command file that assigns the peripheral register structure data sections to the proper memory location. These files are described in Table 7.

Table 7. DSP2802x Peripheral Header Linker Command File

Header File Linker Command File Location Description

DSP2802x_Headers_nonBIOS.cmd DSP2802x_headers\cmd Linker .cmd file to assign the header file

variables in a non-BIOS project. This file must be included in any non-BIOS project that uses the header files. Refer to section 5.2.

DSP2802x_Headers_nonBIOS.cmd DSP2833x_headers\cmd Linker .cmd file to assign the header file

variables in a non-BIOS project. This file must be included in any non-BIOS project that uses the header files. Refer to section 5.2.

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4.3 Example Program Flow

All of the example programs follow a similar recommended flow for setting up a 2802x device. Figure 1 outlines this basic flow:

Reset

Boot Sequence

DSP2802x_CodeStartBranch.asm

Disable WD (Optional)

Branch to C Init Routine

C Init

main() {

Initialize System Control

Boot ROM

During debug – user writes 0x55AA and boot mode to EMU_KEY and EMU_BMODE then Resets device again. Standalone device – boot mode derived from boot pins or OTP_KEY and OTP_BMODE programmed locations.

DSP2802x_CodeStartBranch.asm

Used to re-direct code execution from the boot entry point to the C Init routine. Code can be configured to disable the WatchDog if the WD is timing out before main() is reached. Assigned to the BEGIN section by the linker. Located at 0x000000 for Boot to M0 Located at 0x3F7FF6 for Boot to Flash

C Init Routine

The Compiler's boot.asm which is automatically included with the runtime library. This will set OBJMODE to 28x.

Init PLL, Turn on Peripheral Clocks and set the clock pre-scalers Disable the WatchDog

Configure GPIO Pins to their peripheral function or as an input or output as required by the

Initalize GPIO

Initialize PIE Vector Table

Initalize Peripherals

Example Specific Code

Enable Interrupts

}

Additional Functions and

Interrupt Service Routines

example.

Initalize the entire PIE Vector Table with pointers to default Interrupt Service Routines (ISRs) found in DSP2802x_DefaultIsr.c. It is useful for debug purposes to have the entire table initalized even if the ISR is not going to be used.

Remap PIE vectors used by the example to ISR functions found within the example program.

Initalize the peripherals as required by the example.

Enable the required PIE and CPU interrupts. Any additional code required for the example.

Figure 1. Flow for Example Programs

4.4 Included Examples:

Example Description

adc_soc ADC example to convert two channels: ADCINA4 and ADCINA2. Interrupts are

adc_temp_sensor ADC example – periodically performs conversions on internal channel ADCINA5

adc_temp_sensor_conv ADC example – periodically performs conversions on internal channel ADCINA5,

cpu_timer Configures CPU Timer0 and increments a count each time the ISR is serviced. ecap_apwm This example sets up the alternate eCAP pins in the APWM mode ecap_capture_pwm Captures the edges of a ePWM signal.

epwm_blanking_window Demonstrates blanking window by filtering out digital compare events

epwm_dceventtrip Sets up digital compare events, and uses combinations of these events to set

epwm_dcevent_trip_comp Sets up digital compare events with comparator inputs and uses combinations of

epwm_deadband Example deadband generation via ePWM3 epwm_timer_interrupts Starts ePWM1-ePWM6 timers. Every period an interrupt is taken for each ePWM. epwm_trip_zone Uses the trip zone signals to set the ePWM signals to a particular state. epwm_up_aq Generate a PWM waveform using an up count time base ePWM1-ePWM3 are

epwm_updown_aq Generate a PWM waveform using an up/down time base. ePWM- ePWM3 are

eqep_freqcal Frequency cal using eQEP1 eqep_pos_speed Pos/speed calculation using eQEP1 external_interrupt Configures GPIO0 as XINT1 and GPIO1 as XINT2. The interrupts are fired by

flash_f28027 ePWM timer interrupt project moved from SARAM to Flash for the F28027 device.

gpio_setup Three examples of different pinout configurations. gpio_toggle Toggles all of the I/O pins using different methods – DATA, SET/CLEAR and

hrpwm Sets up ePWM1-ePWM4 and controls the edge of output A using the HRPWM

hrpwm_duty_sfo_v6 Use TI's MEP Scale Factor Optimizer (SFO) library to change the HRPWM duty

hrpwm_prdup_sfo_v6 Use TI’s MEP Scale Factor Optimizer (SFO) library to change the HRPWM period

hrpwm_prdupdown_sfo_v6 Use TI’s MEP Scale Factor Optimizer (SFO) library to change the HRPWM period

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Table 8. Included Examples

enabled and PWM1 is configured to generate a periodic ADC SOC – ADCINT1.

which is connected to the ADC temperature sensor.

connected to the ADC temperature sensor, and converts the ADC result value to Celsius or Kelvins. Only works on TMS 2802x devices.

around CTR = 0.

ePWM signals to a particular state.

these events to set ePWM signals to a particular state.

used.

toggling GPIO30 and GPIO31 which are connected to XINT1 (GPIO0) and XINT2 (GPIO1) externally by the user.

Includes steps that were used to convert the project from SARAM to Flash. Some interrupt service routines are copied from FLASH to SARAM for faster execution.

TOGGLE registers. The pins can be observed using an oscilloscope.

extension. Both rising edge and falling edge are controlled.

cycle.

in up-count mode.

in up-down count mode.

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Included Examples Continued…

hrpwm_slider This is the same as the hrpwm example except the control of CMPAHR is now

i2c_eeprom Communicate with an EEPROM via I2C lpm_haltwake Puts device into low power halt mode. GPIO0 is configured to wake the device from

lpm_idlewake Puts device into low power idle mode. GPIO0 is configured as XINT1 pin. When an

lpm_standbywake Puts device into low power standby mode. GPIO0 is configured to wake the device

osc_comp Runs the oscillator compensation function on internal oscillator 1 or 2 to maintain

sci_echoback SCI-A example that can be used to echoback to a terminal program such as

scia_loopback SCI-A example that uses the peripheral’s loop-back test mode to send data. scia_loopback_interrupts SCI-A example that uses the peripheral’s loop-back test mode to send data. Both

spi_loopback SPI-A example that uses the peripherals loop-back test mode to send data. spi_loopback_interrupts SPI-A example that uses the peripherals loop-back test mode to send data. Both

sw_prioritized_interrupts The standard hardware prioritization of interrupts can be used for most applications.

timed_led_blink This example blinks GPIO34 (LED on the control card) at a rate of 1 Hz using CPU

watchdog Illustrates feeding the dog and re-directing the watchdog to an interrupt.

controlled by the user via a slider bar. The included .gel file sets up the slider.

halt when an external high-low-high pulse is applied to it.

XINT1 interrupt occurs due to a falling edge on GPIO0, the device is woken from idle.

from halt when an external high-low-high pulse is applied to it.

oscillator frequency across temperature. Only works on TMS 2802x devices.

hyperterminal. A transceiver and a connection to a PC is required.

interrupts and FIFOs are used in this example.

This example shows a method for software to re-prioritize interrupts if required.

Timer 0.

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4.5 Executing the Examples From Flash

Most of the DSP2802x examples execute from SARAM in “boot to SARAM” mode. One example, DSP2802x_examples_ccsv4\flash_f28027, executes from flash memory in “boot to flash” mode. This example is the PWM timer interrupt example with the following changes made to execute out of flash:

1. Change the linker command file to link the code to flash.

Remove 28027_RAM_lnk.cmd from the project and link one of the flash based linker files (ex: F28027.cmd, F28026.cmd, F28023.cmd, or F28022.cmd, F28021.cmd, F28020.cmd, F280200.cmd). These files are located in the <base>DSP2802x_common\cmd\ directory.

2. Link DSP2802x_common\source\DSP2802x_CSMPasswords.asm to the project.

This file contains the passwords that will be programmed into the Code Security Module (CSM) password locations. Leaving the passwords set to 0xFFFF during development is recommended as the device can easily be unlocked. For more information on the CSM refer to the appropriate System Control and Interrupts Reference Guide.

3. Modify the source code to copy all functions that must be executed out of SARAM from their load address in flash to their run address in SARAM.

In particular, the flash wait state initialization routine must be executed out of SARAM. In the DSP2802x, functions that are to be executed from SARAM have been assigned to the ramfuncs section by compiler CODE_SECTION #pragma statements as shown in the example below.

/******************************************************************** * DSP2802x_common\source\DSP2802x_SysCtrl.c ********************************************************************/

#pragma CODE_SECTION(InitFlash, "ramfuncs");

The ramfuncs section is then assigned to a load address in flash and a run address in SARAM by the memory linker command file as shown below:

/******************************************************************** * DSP2802x_common\include\F28027.cmd ********************************************************************/ SECTIONS { ramfuncs : LOAD = FLASHA, RUN = PRAML0, LOAD_START(_RamfuncsLoadStart), LOAD_END(_RamfuncsLoadEnd), RUN_START(_RamfuncsRunStart), PAGE = 0 }

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The linker will assign symbols as specified above to specific addresses as follows:

Address Symbol

Load start address RamfuncsLoadStart Load end address RamfuncsLoadEnd Run start address RamfuncsRunStart

These symbols can then be used to copy the functions from the Flash to SARAM using the included example MemCopy routine or the C library standard memcopy() function.

To perform this copy from flash to SARAM using the included example MemCopy function:

a. Link the file DSP2802x_common\source\DSP2802x_MemCopy.c to the project.

c. Add the following function prototype to the example source code. This is done for

you in the DSP2802x_Examples.h file.

/******************************************************************** * DSP2802x_common\include\DSP2802x_Examples.h ********************************************************************/

MemCopy(&RamfuncsLoadStart, &RamfuncsLoadEnd, &RamfuncsRunStart);

d. Add the following variable declaration to your source code to tell the compiler that

these variables exist. The linker command file will assign the address of each of these variables as specified in the linker command file as shown in step 3. For the DSP2802x example code this has is already done in DSP2802x_Examples.h.

/******************************************************************** * DSP2802x_common\include\DSP2802x_GlobalPrototypes.h ********************************************************************/

extern Uint16 RamfuncsLoadStart; extern Uint16 RamfuncsLoadEnd; extern Uint16 RamfuncsRunStart;

e. Modify the code to call the example MemCopy function for each section that needs to

be copied from flash to SARAM.

/******************************************************************** * DSP2802x_examples_ccsv4\flash_f28027 source file ********************************************************************/

MemCopy(&RamfuncsLoadStart, &RamfuncsLoadEnd, &RamfuncsRunStart);

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4. Modify the code to call the flash initialization routine:

This function will initialize the wait states for the flash and enable the Flash Pipeline mode.

/******************************************************************** * DSP2802x peripheral example .c file ********************************************************************/

InitFlash();

5. Set the required jumpers for “boot to Flash” mode.

The required jumper settings for each boot mode are shown in Table 9,

Table 10, and Table 11.

Table 9. 2802x Boot Mode Settings

GPIO37

TDO

X X 1 EMU Mode 0 0 0 Parallel I/O 0 1 0 SCI 1 0 0 Wait 1 1 0 “Get Mode”

GPIO34

CMP2OUT

TRSTn

Mode

Table 10. 2802x EMU Boot Modes (Emulator Connected)

EMU_KEY

0x0D00

!= 0x55AA x Wait

0x55AA

EMU_BMODE

0x0D01

0x0000 Parallel I/O

0x0001 SCI 0x0002 Wait 0x0003 Get Mode 0x0004 SPI 0x0005 I2C 0x0006 OTP 0x0007 Wait 0x0008 Wait

0x000A Boot to RAM

0x000B Boot to FLASH

Other Wait

Boot Mode Selected

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Table 11. 2802x GET Boot Modes (Emulator Disconnected)

OTP_KEY

0x3D7BFE

!= 0x55AA x Get Mode - Flash

0x55AA

OTP_BMODE

0x3D7BFF

0x0001 Get Mode - SCI

0x0003 Get Mode – Flash

0x0004 Get Mode - SPI 0x0005 Get Mode - I2C 0x0006 Get Mode - OTP

Other Get Mode - Flash

Boot Mode Selected

When the emulator is connected for debugging:

When the emulator is not connected for debugging:

SCI or Parallel I/O boot mode can be selected directly via the GPIO pins, or OTP_KEY at address 0x3D7BFE and OTP_BMODE at address 0x3D7BFF can be programmed for the desired boot mode per the tables above

Refer to the documentation for your hardware platform for information on configuring the boot mode selection pins.

For more information on the ‘2802x boot modes refer to the appropriate Boot ROM Reference Guide.

6. Program the device with the built code.

In Code Composer Studio v4, when code is loaded into the device during debug, it automatically programs to flash memory (if command linker file has any code allocated to flash memory).

This can also be done using SDFlash available from Spectrum Digital’s website (www.spectrumdigital.com)

These tools will be updated to support new devices as they become available. Please check for updates.

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5 Steps for Incorporating the Header Files and Sample Code

Follow these steps to incorporate the peripheral header files and sample code into your own projects. If you already have a project that uses the DSP280x or DSP281x header files then also refer to Section 7 for migration tips.

5.1 Before you begin

Before you include the header files and any sample code into your own project, it is recommended that you perform the following:

1. Load and step through an example project.

Load and step through an example project to get familiar with the header files and sample code. This is described in Section 4.

2. Create a copy of the source files you want to use.

DSP2802x_headers: code required to incorporate the header files into your project DSP2802x_common: shared source code much of which is used in the example

projects. DSP2802x_examples_ccsv4: ‘2802x example projects that use the header files and shared code.

5.2 Including the DSP2802x Peripheral Header Files

Including the DSP2802x header files in your project will allow you to use the bit-field structure approach in your code to access the peripherals on the device. To incorporate the header files in a new or existing project, perform the following steps:

1. #include “DSP2802x_Device.h” (or #include “DSP28x_Project.h” ) in your source files.

The DSP2802x_Device.h include file will in-turn include all of the peripheral specific header files and required definitions to use the bit-field structure approach to access the peripherals.

/******************************************************************** * User’s source file ********************************************************************/

#include “DSP2802x_Device.h”

Another option is to #include “DSP28x_Project.h” in your source files, which in-turn includes “DSP2802x_Device.h” and “DSP2802x_Examples.h” (if it is not necessary to include common source files in the user project, the #include “DSP2802x_Examples.h” line can be deleted). Due to the device-generic nature of the file name, user code is easily ported between different device header files.

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/******************************************************************** * User’s source file ********************************************************************/

#include “DSP28x_Project.h”

2. Edit DSP2802x_Device.h and select the target you are building for:

In the below example, the file is configured to build for the ‘28027 device.

/******************************************************************** * DSP2802x_headers\include\DSP2802x_Device.h ********************************************************************/ #define TARGET 1 #define DSP28_28027 TARGET // Selects '28027 #define DSP28_28026 0 // Selects '28026 #define DSP28_28023 0 // Selects '28023… etc

By default, the ‘28027 device is selected.

3. Link the source file DSP2802x_GlobalVariableDefs.c to the project.

This file is found in the DSP2802x_headers\source\ directory and includes:

– Declarations for the variables that are used to access the peripheral registers.

– Data section #pragma assignments that are used by the linker to place the variables

in the proper locations in memory.

4. Link the appropriate DSP2802x header linker command file to the project.

As described in Section 3, when using the DSP2802x header file approach, the data sections of the peripheral register structures are assigned to the memory locations of the peripheral registers by the linker.

To perform this memory allocation in your project, one of the following linker command files located in DSP2802x_headers\cmd\ must be included in your project:

– For non-DSP/BIOS† projects: DSP2802x_Headers_nonBIOS.cmd

– For DSP/BIOS projects: DSP2802x_Headers_BIOS.cmd

†

DSP/BIOS is a trademark of Texas Instruments

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The method for linking the header linker file to the project depends on personal preference.

Method #1:

a. Right-click on the project in the project window of the C/C++ Projects perspective.

b. Select Link Files to Project…

c. Navigate to the DSP2802x_headers\cmd directory on your system and select the

desired .cmd file.

Note: The limitation with Method #1 is that the path to <base>\DSP2802x_headers\cmd\<cmd file>.cmd is fixed on your PC. If you move

the installation directory to another location on your PC, the project will “break” because it still expects the .cmd file to be in the original location. Use Method #2 if you are using “linked variables” in your project to ensure your project/installation directory is portable across computers and different locations on the same PC. (For more information, see:

http://tiexpressdsp.com/index.php/Portable_Projects_in_CCSv4_for_C2000)

Method #2:

a. Right-click on the project in the project window of the C/C++ Projects perspective.

b. Select New->File.

c. Click on the Advanced>> button to expand the window.

d. Check the Link to file in the file system checkbox.

e. Select the Variables… button. From the list, pick the linked variable (macro defined in

your macros.ini file) associated with your installation directory. (For the 2802x header

files, this is INSTALLROOT_2802X_V<version #>). For more information on linked

variables and the macros.ini file, see:

http://tiexpressdsp.com/index.php/Portable_Projects_in_CCSv4_for_C2000#Method_

.232_for_Linking_Files_to_Project:

f. Click on the Extend…” button. Navigate to the desired .cmd file and select OK.

5. Add the directory path to the DSP2802x header files to your project.

To specify the directory where the header files are located:

a. Open the menu: Project->Properties.

b. In the menu on the left, select “C/C++ Build”.

c. In the “Tool Settings” tab, Select “C2000 Compiler -> Include Options:”

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d. In the “Add dir to #include search path (--include_path, -I” window, select the “Add”

icon in the top right corner.

e. Select the “File system…” button and navigate to the directory path of

DSP2802x_headers\include on your system.

6. Additional suggested build options:

The following are additional compiler and linker options. The options can all be set via the Project-> Properties->Tool Settings sub-menus.

– C2000 Compiler:

 -ml Select Runtime Modeul Options and check –ml

Build for large memory model. This setting allows data sections to reside anywhere within the 4M-memory reach of the 28x devices.

 -pdr Select Diagnostic Options and check –pdr

Issue non-serious warnings. The compiler uses a warning to indicate code that is valid but questionable. In many cases, these warnings issued by enabling -pdr can alert you to code that may cause problems later on.

– C2000 Linker:

 -w Select Diagnostics and check –w

Warn about output sections. This option will alert you if any unassigned memory sections exist in your code. By default the linker will attempt to place any unassigned code or data section to an available memory location without alerting the user. This can cause problems, however, when the section is placed in an unexpected location.

 -e Select Symbol Management and enter Program Entry Point –e

Defines a global symbol that specifies the primary entry point for the output module. For the DSP2802x examples, this is the symbol “code_start”. This

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symbol is defined in the DSP2802x_common\source\DSP2802x_CodeStartBranch.asm file. When you load the code in Code Composer Studio, the debugger will set the PC to the address of this symbol. If you do not define a entry point using the –e option, then the linker will use _c_int00 by default.

5.3 Including Common Example Code

Including the common source code in your project will allow you to leverage code that is already written for the device. To incorporate the shared source code into a new or existing project, perform the following steps:

1. #include “DSP2802x_Examples.h” (or “DSP28x_Project.h”) in your source files.

The “DSP2802x_Examples.h” include file will include common definitions and declarations used by the example code.

/******************************************************************** * User’s source file ********************************************************************/

#include “DSP2802x_Examples.h”

Another option is to #include “DSP28x_Project.h” in your source files, which in-turn includes “DSP2802x_Device.h” and “DSP2802x_Examples.h”. Due to the devicegeneric nature of the file name, user code is easily ported between different device header files.

/******************************************************************** * User’s source file ********************************************************************/

#include “DSP28x_Project.h”

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2. Add the directory path to the example include files to your project.

To specify the directory where the header files are located:

a. Open the menu: Project->Properties.

b. In the menu on the left, select “C/C++ Build”.

c. In the “Tool Settings” tab, Select “C2000 Compiler -> Include Options:”

d. In the “Add dir to #include search path (--include_path, -I” window, select the “Add”

icon in the top right corner.

e. Select the “File system…” button and navigate to the directory path of

DSP2802x_headers\include on your system.

3. Link a linker command file to your project.

The following memory linker .cmd files are provided as examples in the

DSP2802x_common\cmd directory. For getting started the basic 28027_RAM_lnk.cmd file is suggested and used by most of the examples.

Table 12. Included Main Linker Command Files

Memory Linker Command

File Examples

28027_RAM_lnk.cmd DSP2802x_common\cmd 28027 memory linker command file.

28026_RAM_lnk.cmd DSP2802x_common\cmd 28026 SARAM memory linker command

28023_RAM_lnk.cmd DSP2802x_common\cmd 28023 SARAM memory linker command

28022_RAM_lnk.cmd DSP2802x_common\cmd 28022 SARAM memory linker command

Location Description

Includes all of the internal SARAM blocks on a 28027 device. “RAM” linker files do not include flash or OTP blocks.

file.

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file.

28021_RAM_lnk.cmd DSP2802x_common\cmd 28021 SARAM memory linker command

file.

28020_RAM_lnk.cmd DSP2802x_common\cmd 28020 SARAM memory linker command

file.

280200_RAM_lnk.cmd DSP2802x_common\cmd 280200 SARAM memory linker command

file.

F28027.cmd DSP2802x_common\cmd F28027 memory linker command file.

Includes all Flash, OTP and CSM

password protected memory locations. F28026.cmd DSP2802x_common\cmd F28026 memory linker command file. F28023.cmd DSP2802x_common\cmd F28023 memory linker command file. F28022.cmd DSP2802x_common\cmd F28022 memory linker command file. F28021.cmd DSP2802x_common\cmd F28021 memory linker command file. F28020.cmd DSP2802x_common\cmd F28020 memory linker command file. F280200.cmd DSP2802x_common\cmd F280200 memory linker command file.

4. Set the CPU Frequency

In the DSP2802x_common\include\DSP2802x_Examples.h file specify the proper CPU frequency. Some examples are included in the file.

/******************************************************************** * DSP2802x_common\include\DSP2802x_Examples.h ********************************************************************/ …… #define CPU_RATE 16.667L // for a 60MHz CPU clock speed (SYSCLKOUT) //#define CPU_RATE 20.000L // for a 50MHz CPU clock speed (SYSCLKOUT) //#define CPU_RATE 25.000L // for a 40MHz CPU clock speed (SYSCLKOUT) ……

5. Link desired common source files to the project.

The common source files are found in the DSP2802x_common\source\ directory.

6. Include .c files for the PIE.

Since all catalog ‘2802x applications make use of the PIE interrupt block, you will want to include the PIE support .c files to help with initializing the PIE. The shell ISR functions can be used directly or you can re-map your own function into the PIE vector table provided. A list of these files can be found in section 8.2.1.

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6 Troubleshooting Tips & Frequently Asked Questions

• In the examples, what do “EALLOW;” and “EDIS;” do?

EALLOW; is a macro defined in DSP2802x_Device.h for the assembly instruction EALLOW and likewise EDIS is a macro for the EDIS instruction. That is EALLOW; is the same as embedding the assembly instruction asm(“ EALLOW”);

Several control registers on the 28x devices are protected from spurious CPU writes by the EALLOW protection mechanism. The EALLOW bit in status register 1 indicates if the protection is enabled or disabled. While protected, all CPU writes to the register are ignored and only CPU reads, JTAG reads and JTAG writes are allowed. If this bit has been set by execution of the EALLOW instruction, then the CPU is allowed to freely write to the protected registers. After modifying the registers, they can once again be protected by executing the EDIS assembly instruction to clear the EALLOW bit.

For a complete list of protected registers, refer to TMS320x2802x System Control and Interrupts Reference Guide .

• Peripheral registers read back 0x0000 and/or cannot be written to.

There are a few things to check:

• Peripheral registers cannot be modified or unless the clock to the specific peripheral is enabled. The function InitPeripheralClocks() in the DSP2802x_common\source directory shows an example of enabling the peripheral clocks.

• Some peripherals are not present on all 2802x family derivatives. Refer to the device datasheet for information on which peripherals are available.

• The EALLOW bit protects some registers from spurious writes by the CPU. If your program seems unable to write to a register, then check to see if it is EALLOW protected. If it is, then enable access using the EALLOW assembly instruction. TMS320x2802x System Control and Interrupts Reference Guide for a complete list of EALLOW protected registers.

• Memory block L0, L1 read back all 0x0000.

In this case most likely the code security module is locked and thus the protected memory locations are reading back all 0x0000. Refer to the for information on the code security module.

• Code cannot write to L0 or L1 memory blocks.

In this case most likely the code security module is locked and thus the protected memory locations are reading back all 0x0000. Code that is executing from outside of the protected cannot read or write to protected memory while the CSM is locked. Refer to the TMS320x2802x Control and Interrupts Reference Guide for information on the code security module

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• A peripheral register reads back ok, but cannot be written to.

The EALLOW bit protects some registers from spurious writes by the CPU. If your program seems unable to write to a register, then check to see if it is EALLOW protected. If it is, then enable access using the EALLOW assembly instruction. TMS320x2802x System Control and Interrupts Reference Guide for a complete list of EALLOW protected registers.

• I re-built one of the projects to run from Flash and now it doesn’t work. What could

be wrong?

Make sure all initialized sections have been moved to flash such as .econst and .switch.

If you are using SDFlash, make sure that all initialized sections, including .econst, are allocated to page 0 in the linker command file (.cmd). SDFlash will only program sections in the .out file that are allocated to page 0.

• Why do the examples populate the PIE vector table and then re-assign some of the

function pointers to other ISRs?

The examples share a common default ISR file. This file is used to populate the PIE vector table with pointers to default interrupt service routines. Any ISR used within the example is then remapped to a function within the same source file. This is done for the following reasons:

– The entire PIE vector table is enabled, even if the ISR is not used within the example.

This can be very useful for debug purposes.

– The default ISR file is left un-modified for use with other examples or your own

project as you see fit.

– It illustrates how the PIE table can be updated at a later time.

• When I build the examples, the linker outputs the following: warning: entry point

other than _c_int00 specified. What does this mean?

This warning is given when a symbol other then _c_int00 is defined as the code entry point of the project. For these examples, the symbol code_start is the first code that is executed after exiting the boot ROM code and thus is defined as the entry point via the – e linker option. This symbol is defined in the DSP2802x_CodeStartBranch.asm file. The entry point symbol is used by the debugger and by the hex utility. When you load the code, CCS will set the PC to the entry point symbol. By default, this is the _c_int00 symbol which marks the start of the C initialization routine. For the DSP2802x examples, the code_start symbol is used instead. Refer to the source code for more information.

• When I build many of the examples, the compiler outputs the following: remark:

controlling expression is constant. What does this mean?

Some of the examples run forever until the user stops execution by using a while(1) {} loop The remark refers to the while loop using a constant and thus the loop will never be exited.

• When I build some of the examples, the compiler outputs the following: warning:

statement is unreachable. What does this mean?

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Some of the examples run forever until the user stops execution by using a while(1) {} loop. If there is code after this while(1) loop then it will never be reached.

• I changed the build configuration of one of the projects from “Debug” to “Release”

and now the project will not build. What could be wrong?

When you switch to a new build configuration (Project->Active Build Configuration) the compiler and linker options changed for the project. The user must enter other options such as include search path and the library search path. Open the build options menu (Project-> Options) and enter the following information:

– C2000 Compiler, Include Options: Include search path

– C2000 Linker, File Search Path: Library search path

– C2000 Linker, File Search Path: Include libraries (ie rts2800_ml.lib)

Refer to section 5 for more details.

• In the flash example I loaded the symbols and ran to main. I then set a breakpoint

but the breakpoint is never hit. What could be wrong?

In the Flash example, the InitFlash function and several of the ISR functions are copied out of flash into SARAM. When you set a breakpoint in one of these functions, Code Composer will insert an ESTOP0 instruction into the SARAM location. When the ESTOP0 instruction is hit, program execution is halted. CCS will then remove the ESTOP0 and replace it with the original opcode. In the case of the flash program, when one of these functions is copied from Flash into SARAM, the ESTOP0 instruction is overwritten code. This is why the breakpoint is never hit. To avoid this, set the breakpoint after the SARAM functions have been copied to SARAM.

• The eCAN control registers require 32-bit write accesses.

The compiler will instead make a 16-bit write accesses if it can in order to improve codesize and/or performance. This can result in unpredictable results.

One method to avoid this is to create a duplicate copy of the eCAN control registers in RAM. Use this copy as a shadow register. First copy the contents of the eCAN register you want to modify into the shadow register. Make the changes to the shadow register and then write the data back as a 32-bit value. This method is shown in the DSP2802x_examples_ccsv4\ ecan_back2back example project.

6.1 Effects of read-modify-write instructions.

When writing any code, whether it be C or assembly, keep in mind the effects of read-modifywrite instructions.

The ‘28x DSP will write to registers or memory locations 16 or 32-bits at a time. Any instruction that seems to write to a single bit is actually reading the register, modifying the single bit, and then writing back the results. This is referred to as a read-modify-write instruction. For most registers this operation does not pose a problem. A notable exception is:

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6.1.1 Registers with multiple flag bits in which writing a 1 clears that flag.

For example, consider the PIEACK register. Bits within this register are cleared when writing a 1 to that bit. If more then one bit is set, performing a read-modify-write on the register may clear more bits then intended.

The below solution is incorrect. It will write a 1 to any bit set and thus clear all of them:

/******************************************************************** * User’s source file ********************************************************************/

PieCtrl.PIEACK.bit.Ack1 = 1; // INCORRECT! May clear more bits.

The correct solution is to write a mask value to the register in which only the intended bit will have a 1 written to it:

/******************************************************************** * User’s source file ********************************************************************/

#define PIEACK_GROUP1 0x0001 …… PieCtrl.PIEACK.all = PIEACK_GROUP1; // CORRECT!

6.1.2 Registers with Volatile Bits.

Some registers have volatile bits that can be set by external hardware.

Consider the PIEIFRx registers. An atomic read-modify-write instruction will read the 16-bit register, modify the value and then write it back. During the modify portion of the operation a bit in the PIEIFRx register could change due to an external hardware event and thus the value may get corrupted during the write.

The rule for registers of this nature is to never modify them during runtime. Let the CPU take the interrupt and clear the IFR flag.

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7 Migration Tips for moving from the TMS320x280x or TMS320x281x

header files to the TMS320x2802x header files

This section includes suggestions for moving a project from the 280x header files to the 2802x header files.

1. Create a copy of your project to work with or back-up your current project.

2. Open the project file(s) in a text editor

In Code Composer Studio v4.x:

Open the .project, .cdtbuild, and macros.ini files in your example folder. Replace all instances of 280x with 2802x so that the appropriate source files and build options are used. Check the path names to make sure they point to the appropriate header file and source code directories. Also replace the header file version number for the paths and macro names as well where appropriate. For instance, if a macro name was INSTALLROOT_280X_V170 for your 280x project using 280x header files V1.70, change this to INSTALLROOT_2802X_V110 to migrate to the 2802x header files V1.10. If not using the default macro name for your header file version, be sure to change your macros according to your chosen macro name in the .project, .cdtbuild, and macros.ini files.

3. Load the project into Code Composer Studio

Use the Edit-> find in files dialog to find instances of DSP280x_Device.h and DSP280x_Example.h for 280x header files. Replace these with DSP2802x_Device.h and DSP2802x_Example.h respectively (or instead with one DSP2802x_Project.h file).

4. Make sure you are using the correct linker command files (.cmd) appropriate for your device and for the DSP2802x header files.

You will have one file for the memory definitions and one file for the header file structure definitions. Using a 280x memory file can cause issues since the H0 memory block has been split, renamed, and/or moved on the 2802x.

5. Build the project.

The compiler will highlight areas that have changed. If migrating from the TMS320x280x header files, code should be mostly compatible after all instances of DSP280x are replaced with DSP2802x in all relevant files, and the above steps are taken. Additionally, several bits have been removed and/or replaced. See Table 13.

Table 13. Summary of Register and Bit-Name Changes from DSP280x V1.60

DSP2802x V1.00

Bit Name

Peripheral Register Old New Comment

SysCtrlRegs

XCLK Reserved(bit 6) XCLKINSEL(bit 6) On 2802x devices, XCLKIN can be fed via

a GPIO pin. This bit selects either GPIO38 (default) or GPIO19 as XCLKIN input source.

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PLLSTS CLKINDIV(bit 1) DIVSEL (bits 8,7) DIVSEL allows more values by which

CLKIN can be divided.

Additionally, unlike the DSP280x devices, the DSP2802x devices run off an internal oscillator (INTOSC1) by default. To switch between the 2 available internal clock sources and the traditional external oscillator clock source, a new register in the System Control register space – CLKCTL – is available.

8 Packet Contents:

This section lists all of the files included in the release.

8.1 Header File Support – DSP2802x_headers

The DSP2802x header files are located in the <base>\DSP2802x_headers\ directory.

8.1.1 DSP2802x Header Files – Main Files

The following files must be added to any project that uses the DSP2802x header files. Refer to section 5.2 for information on incorporating the header files into a new or existing project.

Table 14. DSP2802x Header Files – Main Files

File Location Description

DSP2802x_Device.h DSP2802x_headers\include Main include file. Include this one file in any

of your .c source files. This file in-turn includes all of the peripheral specific .h files listed below. In addition the file includes typedef statements and commonly used mask values. Refer to section 5.2.

DSP2802x_GlobalVariableDefs.c DSP2802x_headers\source Defines the variables that are used to access

the peripheral structures and data section #pragma assignment statements. This file must be included in any project that uses the header files. Refer to section 5.2.

DSP2802x_Headers_nonBIOS.cmd DSP2802x_headers\cmd Linker .cmd file to assign the header file

variables in a non-BIOS project. This file must be included in any non-BIOS project that uses the header files. Refer to section

5.2.

DSP2802x_Headers_nonBIOS.cmd DSP2802x_headers\cmd Linker .cmd file to assign the header file

variables in a non-BIOS project. This file must be included in any non-BIOS project that uses the header files. Refer to section

5.2.

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8.1.2 DSP2802x Header Files – Peripheral Bit-Field and Register Structure Definition Files

The following files define the bit-fields and register structures for each of the peripherals on the 2802x devices. These files are automatically included in the project by including DSP2802x_Device.h. Refer to section 4.2 for more information on incorporating the header files into a new or existing project.

Table 15. DSP2802x Header File Bit-Field & Register Structure Definition Files

File Location Description

DSP2802x_Adc.h DSP2802x_headers\include ADC register structure and bit-field definitions. DSP2802x_BootVars.h DSP2802x_headers\include External boot variable definitions. DSP2802x_Comp.h DSP2802x_headers\include Comparator register structure and bit-field

definitions.

DSP2802x_CpuTimers.h DSP2802x_headers\include CPU-Timer register structure and bit-field

definitions. DSP2802x_DevEmu.h DSP2802x_headers\include Emulation register definitions DSP2802x_ECap.h DSP2802x_headers\include eCAP register structures and bit-field definitions. DSP2802x_EPwm.h DSP2802x_headers\include ePWM register structures and bit-field definitions. DSP2802x_Gpio.h DSP2802x_headers\include General Purpose I/O (GPIO) register structures

and bit-field definitions. DSP2802x_I2c.h DSP2802x_headers\include I2C register structure and bit-field definitions. DSP2802x_NmiIntrupt.h DSP2802x_headers\include NMI interrupt register structure and bit-field

definitions DSP2802x_PieCtrl.h DSP2802x_headers\include PIE control register structure and bit-field

definitions. DSP2802x_PieVect.h DSP2802x_headers\include Structure definition for the entire PIE vector table. DSP2802x_Sci.h DSP2802x_headers\include SCI register structure and bit-field definitions. DSP2802x_Spi.h DSP2802x_headers\include SPI register structure and bit-field definitions. DSP2802x_SysCtrl.h DSP2802x_headers\include System register definitions. Includes Watchdog,

PLL, CSM, Flash/OTP, Clock registers. DSP2802x_XIntrupt.h DSP2802x_headers\include External interrupt register structure and bit-field

definitions.

8.1.3 Variable Names and Data Sections

This section is a summary of the variable names and data sections allocated by the DSP2802x_headers\source\DSP2802x_GlobalVariableDefs.c file. Note that all peripherals may not be available on a particular 2802x device. Refer to the device datasheet for the peripheral mix available on each 2802x family derivative.

Table 16. DSP2802x Variable Names and Data Sections

Peripheral Starting Address Structure Variable Name

ADC 0x007100 AdcRegs ADC Mirrored Result Registers 0x000B00 AdcMirror Code Security Module 0x000AE0 CsmRegs Code Security Module Password

Locations COMP1 0x006400 Comp1Regs COMP2 0x006420 Comp2Regs CPU Timer 0 0x000C00 CpuTimer0Regs CPU Timer 1 0x000C08 CpuTimer1Regs CPU Timer 2 0x000C10 CpuTimer2Regs Device and Emulation Registers 0x000880 DevEmuRegs System Power Control Registers 0x000985 SysPwrCtrlRegs ePWM1 0x006800 EPwm1Regs ePWM2 0x006840 EPwm2Regs ePWM3 0x006880 EPwm3Regs ePWM4 0x0068C0 EPwm4Regs eCAP1 0x006A00 ECap1Regs External Interrupt Registers 0x007070 XIntruptRegs Flash & OTP Configuration Registers 0x000A80 FlashRegs General Purpose I/O Data Registers 0x006fC0 GpioDataRegs General Purpose Control Registers 0x006F80 GpioCtrlRegs General Purpose Interrupt Registers 0x006fE0 GpioIntRegs I2C 0x007900 I2caRegs NMI Interrupt 0x7060 NmiIntruptRegs PIE Control 0x000CE0 PieCtrlRegs SCI-A 0x007050 SciaRegs SPI-A 0x007040 SpiaRegs

0x3F7FF80x3F7FFF

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CsmPwl

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zedDefaultIsr.c

8.2 Common Example Code – DSP2802x_common

8.2.1 Peripheral Interrupt Expansion (PIE) Block Support

In addition to the register definitions defined in DSP2802x_PieCtrl.h, this packet provides the basic ISR structure for the PIE block. These files are:

Table 17. Basic PIE Block Specific Support Files

File Location Description

DSP2802x_DefaultIsr.c DSP2802x_common\source Shell interrupt service routines (ISRs) for the entire PIE

vector table. You can choose to populate one of functions or re-map your own ISR to the PIE vector table. Note: This file is not used for DSP/BIOS projects.

DSP2802x_DefaultIsr.h DSP2802x_common\include Function prototype statements for the ISRs in

DSP2802x_DefaultIsr.c. Note: This file is not used for

DSP/BIOS projects.

DSP2802x_PieVect.c DSP2802x_common\source Creates an instance of the PIE vector table structure

initialized with pointers to the ISR functions in DSP2802x_DefaultIsr.c. This instance can be copied to the PIE vector table in order to initialize it with the default ISR locations.

In addition, the following files are included for software prioritization of interrupts. These files are used in place of those above when additional software prioritization of the interrupts is required. Refer to the example and documentation in DSP2802x_examples_ccsv4\sw_prioritized_interrupts for more information.

Table 18. Software Prioritized Interrupt PIE Block Specific Support Files

File Location Description

DSP2802x_SWPrioriti

DSP2802x_SWPrioritizedIsrLevels.h DSP2802x_common\include Function prototype statements for the ISRs

DSP2802x_SWPrioritizedPieVect.c DSP2802x_common\source Creates an instance of the PIE vector table

DSP2802x_common\source Default shell interrupt service routines

(ISRs). These are shell ISRs for all of the PIE interrupts. You can choose to populate one of functions or re-map your own interrupt service routine to the PIE vector table. Note: This file is not used for DSP/BIOS projects.

in DSP2802x_DefaultIsr.c. Note: This file

is not used for DSP/BIOS projects.

structure initialized with pointers to the default ISR functions that are included in DSP2802x_DefaultIsr.c. This instance can be copied to the PIE vector table in order to initialize it with the default ISR locations.

8.2.2 Peripheral Specific Files

Several peripheral specific initialization routines and support functions are included in the peripheral .c source files in the DSP2802x_common\src\ directory. These files include:

Table 19. Included Peripheral Specific Files

File Description

DSP2802x_GlobalPrototypes.h Function prototypes for the peripheral specific functions included in these files. DSP2802x_Adc.c ADC specific functions and macros. DSP2802x_Comp.c Comparator specific functions and macros DSP2802x_CpuTimers.c CPU-Timer specific functions and macros. DSP2802x_ECap.c eCAP module specific functions and macros. DSP2802x_EPwm.c ePWM module specific functions and macros. DSP2802x_EPwm_defines.h #define macros that are used for the ePW M examples DSP2802x_Gpio.c General-purpose IO (GPIO) specific functions and macros. DSP2802x_I2C.c I2C specific functions and macros. DSP2802x_I2c_defines.h #define macros that are used for the I2C examples DSP2802x_PieCtrl.c PIE control specific functions and macros. DSP2802x_Sci.c SCI specific functions and macros. DSP2802x_Spi.c SPI specific functions and macros. DSP2802x_SysCtrl.c System control (watchdog, clock, PLL etc) specific functions and macros.

Note: The specific routines are under development and may not all be available as of this release. They will be added and distributed as more examples are developed.

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8.2.3 Utility Function Source Files

Table 20. Included Utility Function Source Files

File Description

DSP2802x_CodeStartBranch.asm Branch to the start of code execution. This is used to re-direct code

execution when booting to Flash, OTP or M0 SARAM memory. An option to

disable the watchdog before the C init routine is included. DSP2802x_DBGIER.asm Assembly function to manipulate the DEBIER register from C. DSP2802x_DisInt.asm Disable interrupt and restore interrupt functions. These functions allow you

to disable INTM and DBGM and then later restore their state. DSP2802x_usDelay.asm Assembly function to insert a delay time in microseconds. This function is

cycle dependant and must be executed from zero wait-stated RAM to be

accurate.

Refer to DSP2802x_examples_ccsv4/adc_soc for an example of its use. DSP2802x_CSMPasswords.asm Include in a project to program the code security module passwords and

reserved locations.

8.2.4 Example Linker .cmd files

Example memory linker command files are located in the DSP2802x_common\cmd directory. For getting started the basic 28027_RAM_lnk.cmd file is suggested and used by many of the included examples.

The L0 SARAM block is mirrored on these devices. For simplicity these memory maps only include one instance of these memory blocks.

Table 21. Included Main Linker Command Files