motor-control-sdk/docs_src/docs/api_guide/examples/sdfm_example.md

SDFM

[TOC]

The ICSS %SDFM driver provides a well defined set of APIs to expose sigma delta interface.

The ICSS %SDFM example invokes these APIs to

• Set %SDFM channels
• Set ACC source, NC OSR, OC OSR, Clock source & Clock inversion
• Enable & disable threshold comparators
• Set high, low & zero cross threshold values
• configure sample trigger time (time for read sample)
• Inform firmware to enable %SDFM mode
• Configure GPIO pins for high, low & zero cross thresholds

Once these steps are executed

• ICSS %SDFM example waits for a interrupt (trigger by %SDFM firmware) to read sample data
• when interrupt occurs, example reads sample data from DMEM and again comes back to waiting loop

ICSS SDFM Example Implementation

Following section describes the Example implementation of ICSS %SDFM on ARM(R5F). \image html SDFM_EXAMPLE_FLOWCHART.png "ICSS SDFM Example"

Important files and directory structure

Folder/Files	Description
${SDK_INSTALL_PATH}/examples/motor_control/icss_sdfm
app_sddf.c & sddf.c	ICSS %SDFM application
${SDK_INSTALL_PATH}/source/current_sense/sdfm
firmware/	Folder containing %SDFM firmware sources
driver/	ICSS %SDFM driver

Supported Combinations

\cond SOC_AM64X

Parameter	Value
CPU + OS	r5fss0-0 freertos
ICSSG	ICSSG0
PRU	PRU0
Toolchain	ti-arm-clang
Board	@VAR_BOARD_NAME_LOWER
Example folder	examples/motorcontrol/sddf

\endcond

\cond SOC_AM243X

Parameter	Value
CPU + OS	r5fss0-0 freertos
ICSSG	ICSSG0
PRU	PRU0
Toolchain	ti-arm-clang
Board	@VAR_BOARD_NAME_LOWER
Example folder	examples/motorcontrol/sddf

\endcond

Steps to Run the Example

Hardware Prerequisites

Other than the basic EVM setup mentioned in \htmllink{@VAR_MCU_SDK_DOCS_PATH/EVM_SETUP_PAGE.html, EVM Setup}, below additional HW is required to run this demo

• TIDEP-01015 3 Axis board
• Interface card connecting EVM and TIDEP-01015 3 Axis board
• Signal generator

Hardware Setup

\image html SDFM_HwSetup_image.PNG "Hardware Setup SDFM"

Build, load and run

• When using CCS projects to build, import the CCS project and build it using the CCS project menu (see \htmllink{@VAR_MCU_SDK_DOCS_PATH/CCS_PROJECTS_PAGE.html, Using SDK with CCS Projects}).
• When using makefiles to build, note the required combination and build using make command (see \htmllink{@VAR_MCU_SDK_DOCS_PATH/MAKEFILE_BUILD_PAGE.html, Using SDK with Makefiles})
• Launch a CCS debug session and run the executable, see \htmllink{@VAR_MCU_SDK_DOCS_PATH/CCS_LAUNCH_PAGE.html, CCS Launch, Load and Run}
• Refer to UART terminal for user interface menu options.

Test Case Description

Test detail	Steps	Pass/fail crieteria
To check raw data for 64 NC OSR	1. Set NC OSR to 64	Resolution of sampled data should be 13.9 bits
	2. Set data read time half of epwm cycle
	3. Set epwm output frequency 20Khz
	4. Draw graph for Raw data	\image html SDFM_sample_output.PNG "NC sample data"
To check raw data for 32 NC OSR	1. Set NC OSR to 32	Resolution of sampled data should be 11.4 bits
	2. Set data read time half of epwm cycle
	3. Set epwm output frequency 20Khz
To check Threshold comparator	1. Set High Threshold to 3500 and low threshold to 2500	Logic analyzer capture for High & Low Thresholds
	2. Set Over current OSR to 32	\image html SDFM_threshold_comparator_salea_capture.png "Logic analyzer Capture"
	3. Probe Ch0 high, low threshold GPIO pins & input signal
	4. Capture signal in Logic analyzer