SMART ARM-based Microcontrollers
AT07912: SAM4L Parallel Capture (PARC) Driver
APPLICATION NOTE
Introduction
®
®
This driver for Atmel | SMART ARM -based microcontrollers provides an
interface for the configuration and management of the Parallel Capture
module.
The Parallel Capture module samples an external 8-bit bus with an external
input clock. It can be connected to a CMOS digital image sensor, an ADC, a
DSP synchronous port, etc.
Devices from the following series can use this module:
•
Atmel | SMART SAM4L
The outline of this documentation is as follows:
•
Prerequisites
•
Module Overview
•
Special Considerations
•
Extra Information
•
Examples
•
API Overview
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Table of Contents
Introduction......................................................................................................................1
1. Software License....................................................................................................... 4
2. Prerequisites..............................................................................................................5
3. Module Overview....................................................................................................... 6
3.1.
3.2.
Features....................................................................................................................................... 6
Concatenated Data Capture.........................................................................................................6
4. Special Considerations.............................................................................................. 7
4.1.
4.2.
4.3.
4.4.
4.5.
I/O Lines....................................................................................................................................... 7
Power Management..................................................................................................................... 7
Clocks...........................................................................................................................................7
DMA..............................................................................................................................................7
Interrupt........................................................................................................................................ 7
5. Extra Information....................................................................................................... 8
6. Examples................................................................................................................... 9
7. API Overview........................................................................................................... 10
7.1.
7.2.
7.3.
Variable and Type Definitions..................................................................................................... 10
7.1.1.
Type parc_callback_t................................................................................................... 10
Structure Definitions................................................................................................................... 10
7.2.1.
Struct parc_config........................................................................................................10
7.2.2.
Struct parc_module......................................................................................................10
Function Definitions.................................................................................................................... 11
7.3.1.
Function parc_clear_status()........................................................................................11
7.3.2.
Function parc_disable()................................................................................................11
7.3.3.
Function parc_disable_callback()................................................................................ 12
7.3.4.
Function parc_disable_events()...................................................................................12
7.3.5.
Function parc_disable_interrupts().............................................................................. 12
7.3.6.
Function parc_enable()................................................................................................13
7.3.7.
Function parc_enable_callback().................................................................................13
7.3.8.
Function parc_enable_events()................................................................................... 14
7.3.9.
7.3.10.
7.3.11.
7.3.12.
7.3.13.
7.3.14.
7.3.15.
7.3.16.
7.3.17.
7.3.18.
Function parc_enable_interrupts()...............................................................................14
Function parc_get_config_defaults()........................................................................... 14
Function parc_get_status().......................................................................................... 15
Function parc_get_version()........................................................................................ 15
Function parc_init()...................................................................................................... 15
Function parc_is_data_ready().................................................................................... 16
Function parc_read()................................................................................................... 16
Function parc_read_interrupt_mask()..........................................................................17
Function parc_register_callback()................................................................................17
Function parc_set_config().......................................................................................... 18
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7.3.19.
7.4.
Function parc_start_capture()......................................................................................18
7.3.20. Function parc_stop_capture()......................................................................................18
7.3.21. Function parc_unregister_callback()............................................................................19
Enumeration Definitions............................................................................................................. 19
7.4.1.
Enum parc_callback_type............................................................................................19
7.4.2.
Enum parc_capture_mode.......................................................................................... 19
7.4.3.
Enum parc_data_size.................................................................................................. 20
7.4.4.
Enum parc_interrupt_source....................................................................................... 20
7.4.5.
Enum parc_sampling_edge......................................................................................... 20
7.4.6.
Enum parc_smode.......................................................................................................20
7.4.7.
Enum parc_status........................................................................................................21
8. Extra Information for Parallel Capture..................................................................... 22
8.1.
8.2.
8.3.
8.4.
Acronyms....................................................................................................................................22
Dependencies.............................................................................................................................22
Errata..........................................................................................................................................22
Module History............................................................................................................................22
9. Examples for Parallel Capture................................................................................. 23
9.1.
9.2.
Quick Start Guide for the PARC driver....................................................................................... 23
9.1.1.
Use Cases................................................................................................................... 23
9.1.2.
PARC Basic Use Case.................................................................................................23
9.1.3.
Setup Steps................................................................................................................. 23
9.1.4.
PARC Basic Usage...................................................................................................... 24
Parallel Capture (PARC) - Example Using GPIO as Stimuli.......................................................24
9.2.1.
Purpose....................................................................................................................... 24
9.2.2.
Requirements.............................................................................................................. 24
9.2.3.
Description...................................................................................................................25
9.2.4.
Main Files.................................................................................................................... 25
9.2.5.
Compilation Information...............................................................................................25
9.2.6.
Usage.......................................................................................................................... 25
10. Document Revision History..................................................................................... 27
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1.
Software License
Redistribution and use in source and binary forms, with or without modification, are permitted provided
that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other materials provided with the distribution.
3. The name of Atmel may not be used to endorse or promote products derived from this software without
specific prior written permission.
4. This software may only be redistributed and used in connection with an Atmel microcontroller product.
THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE EXPRESSLY AND SPECIFICALLY
DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
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2.
Prerequisites
There are no prerequisites for this module.
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3.
Module Overview
The Parallel Capture (PARC) module samples an external 8-bit bus with an external input clock. It can be
connected to a CMOS digital image sensor, an ADC, a DSP synchronous port, etc.
3.1.
Features
The PARC module offers the following features:
•
Captures 8-bit data with an external input clock
•
Data captures can be concatenated to form 16-bit and 32-bit values
•
Two external data enables PCEN1 and PCEN2
•
Four data sample conditions:
•
When PCEN1 is high
•
When PCEN1 and PCEN2 are both high
•
When PCEN1 or PCEN2 are high
•
PC1EN1 and PCEN2 are both inactive i.e. data is sampled without condition
•
Peripheral Direct Memory Access (DMA) is supported
•
Peripheral events are supported
3.2.
Concatenated Data Capture
Captured data bytes are stored in the module's Receive Holding Register (RHR). Concatenated data can
also be stored in the RHR to make 16-bit or 32-bit values, with the first byte received in the Least
Significant Byte (LSB) position. Refer to the diagram entitled "parallel capture waveforms" in the parc
chapter of the device-specific datasheet for more information.
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4.
Special Considerations
4.1.
I/O Lines
The PARC pins are multiplexed with other peripherals. The user application must first configure the I/O
Controller to yield control of the pins.
4.2.
Power Management
The PARC module stops functioning when the system enters a sleep mode that disables its clock.
4.3.
Clocks
The PARC module's clock is generated by the Power Manager. It can be disabled either manually via
software or automatically when the system enters a sleep mode that disables the clocks to the peripheral
bus modules. For correct behavior, the PARC module's clock frequency must be at least twice the PCCK
frequency.
4.4.
DMA
The PARC module's DMA handshake interface is connected to the Peripheral DMA Controller (PDCA).
Using the PARC module's DMA functionality requires the PDCA to be configured first.
4.5.
Interrupt
The PARC interrupt request line is connected to the Nested Vectored Interrupt Controller (NVIC). Using
the PARC interrupt requires that the NVIC to be configured first.
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5.
Extra Information
For extra information, see Extra Information for Parallel Capture. This includes:
•
Acronyms
•
Dependencies
•
Errata
•
Module History
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6.
Examples
For a list of examples related to this driver, see Examples for Parallel Capture.
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7.
API Overview
7.1.
Variable and Type Definitions
7.1.1.
Type parc_callback_t
typedef void(* parc_callback_t )(const struct parc_module *const
module_inst)
PARC interrupt handler callback type.
7.2.
Structure Definitions
7.2.1.
Struct parc_config
PARC configuration structure
Note: This structure should be initialized by the parc_get_config_defaults() function before being further
modified by the user application.
Table 7-1 Members
7.2.2.
Type
Name
Description
enum parc_capture_mode
capture_mode
Capture mode.
enum parc_data_size
dsize
Data size.
enum parc_sampling_edge
sampling_edge
Sampling edge select.
enum parc_smode
smode
Sampling mode.
Struct parc_module
PARC driver structure.
Note: This structure should be initialized by the function parc_init().
Table 7-2 Members
Type
Name
Description
parc_callback_t
callback[]
Array to store callback functions (for PARC driver use
only).
uint8_t
enabled_callback_mask
Bitmask of callbacks enabled/disabled (for PARC
driver use only).
Parc *
hw
Base address of the PARC module.
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Type
Name
Description
struct parc_config * parc_cfg
uint8_t
Pointer to the PARC configuration structure.
registered_callback_mask Bitmask of callbacks registered (for PARC driver use
only).
7.3.
Function Definitions
7.3.1.
Function parc_clear_status()
Clear PARC interrupt(s) status flag.
enum status_code parc_clear_status(
struct parc_module *const module_inst,
const uint32_t status)
Table 7-3 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
[in]
status
A bitmask of interrupt sources to clear
Returns
The clear interrupt operation status.
Table 7-4 Return Values
7.3.2.
Return value
Description
STATUS_OK
The interrupt was cleared successfully
Function parc_disable()
Disable the PARC module.
enum status_code parc_disable(
struct parc_module *const module_inst)
Table 7-5 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The disable procedure status.
Table 7-6 Return Values
Return value
Description
STATUS_OK
The disable procedure was successful
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7.3.3.
Function parc_disable_callback()
Disable a PARC interrupt callback function.
enum status_code parc_disable_callback(
struct parc_module *const module_inst,
enum parc_callback_type type)
Table 7-7 Parameters
Data direction
Parameter name
Description
[in, out]
module_inst
Driver structure pointer
[in]
type
Interrupt callback to disable
Returns
The status of the interrupt callback disable operation.
Table 7-8 Return Values
7.3.4.
Return value
Description
STATUS_OK
Interrupt callback disabled successfully
Function parc_disable_events()
Disable the PARC events mode.
enum status_code parc_disable_events(
struct parc_module *const module_inst)
Table 7-9 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The status of the event disable operation.
Table 7-10 Return Values
7.3.5.
Return value
Description
STATUS_OK
The event was disabled successfully
Function parc_disable_interrupts()
Disable PARC interrupt(s).
void parc_disable_interrupts(
struct parc_module *const module_inst,
enum parc_interrupt_source source)
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Table 7-11 Parameters
7.3.6.
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
[in]
source
Bitmask of interrupt sources to disable
Function parc_enable()
Enable the PARC module.
enum status_code parc_enable(
struct parc_module *const module_inst)
Table 7-12 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The enable procedure status.
Table 7-13 Return Values
7.3.7.
Return value
Description
STATUS_OK
The enable procedure was successful
Function parc_enable_callback()
Enable a PARC interrupt callback function.
enum status_code parc_enable_callback(
struct parc_module *const module_inst,
enum parc_callback_type type)
Note: The callback function will be called from the PARC interrupt handler when the callback's
corresponding interrupt is asserted.
Table 7-14 Parameters
Data direction
Parameter name
Description
[in, out]
module_inst
Driver structure pointer
[in]
type
Interrupt callback to enable
Returns
The status of the interrupt callback enable operation.
Table 7-15 Return Values
Return value
Description
STATUS_OK
Interrupt callback enabled successfully
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7.3.8.
Function parc_enable_events()
Enable the PARC events mode.
enum status_code parc_enable_events(
struct parc_module *const module_inst)
Table 7-16 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The status of the event enable operation.
Table 7-17 Return Values
7.3.9.
Return value
Description
STATUS_OK
The event was enabled successfully
Function parc_enable_interrupts()
Enable PARC interrupt(s).
void parc_enable_interrupts(
struct parc_module *const module_inst,
enum parc_interrupt_source source)
Table 7-18 Parameters
7.3.10.
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
[in]
source
Bitmask of interrupt sources to enable
Function parc_get_config_defaults()
Initialize a PARC configuration structure to default values.
void parc_get_config_defaults(
struct parc_config *const config)
Initializes the supplied PARC configuration structure to a set of known default values.
Note: This function should be called to populate new instances of the configuration structure before
being further modified by the user application.
The default configurations are:
•
Capture every byte
•
Sample the data bus on the rising edge of the PCCK input clock
•
Sample data regardless of the levels of PCEN1 and PCEN2
•
8-bit data width
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Table 7-19 Parameters
7.3.11.
Data direction
Parameter name
Description
[out]
config
Pointer to a PARC configuration structure
Function parc_get_status()
Get the PARC module's current status.
uint32_t parc_get_status(
struct parc_module *const module_inst)
Table 7-20 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The PARC module's current status as a bitmask.
Table 7-21 Return Values
7.3.12.
Return value
Description
PARC_STATUS_EN
PARC is enabled
PARC_STATUS_CS
PARC capture status
PARC_STATUS_DRDY
PARC data ready
PARC_STATUS_OVR
PARC overrun
Function parc_get_version()
Get the PARC module version.
uint32_t parc_get_version(
struct parc_module *const module_inst)
Table 7-22 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The PARC module version.
7.3.13.
Function parc_init()
Initialize the PARC module.
enum status_code parc_init(
struct parc_module *const module_inst,
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Parc *const hw,
struct parc_config *const config)
Initialize the PARC driver structure and the hardware module based on the given configuration structure's
contents.
Table 7-23 Parameters
Data direction
Parameter name
Description
[in, out]
module_inst
Pointer to the PARC driver structure
[in]
hw
Pointer to the PARC module hardware register structure
[in]
config
Pointer to the PARC configuration structure
Returns
The initialization status.
Table 7-24 Return Values
7.3.14.
Return value
Description
STATUS_OK
The initialization was successful
Function parc_is_data_ready()
Check the data ready status of PARC.
bool parc_is_data_ready(
struct parc_module *const module_inst)
Table 7-25 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The PARC data ready status.
Table 7-26 Return Values
7.3.15.
Return value
Description
false
Captured data is not ready
true
Captured data is ready
Function parc_read()
Get PARC data.
enum status_code parc_read(
struct parc_module *const module_inst,
uint32_t * data)
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Table 7-27 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
[out]
data
Pointer to store the captured data in
Returns
The status of the PARC read data request.
Table 7-28 Return Values
7.3.16.
Return value
Description
STATUS_OK
Captured data was read successfully
STATUS_ERR_BUSY
Captured data is not ready
Function parc_read_interrupt_mask()
Get the PARC interrupt mask.
uint32_t parc_read_interrupt_mask(
struct parc_module *const module_inst)
Table 7-29 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Returns
The PARC interrupt mask.
7.3.17.
Function parc_register_callback()
Register a PARC interrupt callback function.
enum status_code parc_register_callback(
struct parc_module *const module,
parc_callback_t const callback_func,
enum parc_callback_type callback_type)
Note: The callback must be enabled by using parc_enable_callback.
Table 7-30 Parameters
Data direction
Parameter name
Description
[in, out]
module
Driver structure pointer
[in]
callback_func
Pointer to a callback function
[in]
callback_type
Interrupt callback type
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Returns
The status of the interrupt callback register operation.
Table 7-31 Return Values
7.3.18.
Return value
Description
STATUS_OK
PARC interrupt callback was registered successfully
Function parc_set_config()
Configure the PARC module.
enum status_code parc_set_config(
struct parc_module *const module_inst,
struct parc_config * config)
Configure the PARC module from the supplied configuration structure.
Table 7-32 Parameters
Data direction
Parameter name
Description
[in]
module_inst
Pointer to the PARC driver structure
[in]
config
Pointer to the PARC configuration structure
Returns
The configuration status.
Table 7-33 Return Values
7.3.19.
Return value
Description
STATUS_OK
The configuration was successful
Function parc_start_capture()
Start a PARC conversion.
void parc_start_capture(
struct parc_module *const module_inst)
Table 7-34 Parameters
7.3.20.
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Function parc_stop_capture()
Stop a PARC conversion.
void parc_stop_capture(
struct parc_module *const module_inst)
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Table 7-35 Parameters
7.3.21.
Data direction
Parameter name
Description
[in]
module_inst
Driver structure pointer
Function parc_unregister_callback()
Unregister a PARC interrupt callback.
enum status_code parc_unregister_callback(
struct parc_module *const module,
enum parc_callback_type callback_type)
Table 7-36 Parameters
Data direction
Parameter name
Description
[in, out]
module
Driver structure pointer
[in]
callback_type
Interrupt callback type
Returns
The status of the interrupt callback unregister operation.
Table 7-37 Return Values
Return value
Description
STATUS_OK
PARC interrupt callback was unregistered successfully
7.4.
Enumeration Definitions
7.4.1.
Enum parc_callback_type
PARC callback type.
Table 7-38 Members
7.4.2.
Enum value
Description
PARC_CALLBACK_DATA_READY
Data ready callback.
PARC_CALLBACK_OVERRUN
Data overrun callback.
Enum parc_capture_mode
PARC captured byte.
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Table 7-39 Members
7.4.3.
Enum value
Description
PARC_BOTH_CAPTURE
Bytes are captured when data is captured every cycle.
PARC_EVEN_CAPTURE
Even bytes are captured when data is captured every two cycles.
PARC_ODD_CAPTURE
Odd bytes are captured when data is captured every two cycles.
Enum parc_data_size
PARC data Size.
Table 7-40 Members
7.4.4.
Enum value
Description
PARC_DSIZE_BYTE
PARC data transfer size is 8-bits.
PARC_DSIZE_HALFWORD
PARC data transfer size is 16-bits.
PARC_DSIZE_WORD
PARC data transfer size is 32-bits.
Enum parc_interrupt_source
PARC interrupt source.
Table 7-41 Members
7.4.5.
Enum value
Description
PARC_INTERRUPT_DRDY
Data ready interrupt.
PARC_INTERRUPT_OVR
Data overrun interrupt.
Enum parc_sampling_edge
PARC sampling edge.
Table 7-42 Members
7.4.6.
Enum value
Description
PARC_RISING_EDGE
Data capture occurs on the rising edge of PCCK.
PARC_FALLING_EDGE
Data capture occurs on the falling edge of PCCK.
Enum parc_smode
PARC sample mode.
Table 7-43 Members
Enum value
Description
PARC_SMODE_PCEN1_H
Data capture occurs with PCEN1 high.
PARC_SMODE_PCEN1_AND_PCEN2_H
Data capture occurs with PCEN1 and PCEN2 high.
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7.4.7.
Enum value
Description
PARC_SMODE_PCEN1_OR_PCEN2_H
Data capture occurs with either PCEN1 or PCEN2 high.
PARC_SMODE_ALWAYS
Data capture always occurs.
Enum parc_status
PARC status.
Table 7-44 Members
Enum value
Description
PARC_STATUS_EN
PARC module enable/disable status.
PARC_STATUS_CS
PARC Capture mode enable/disable status.
PARC_STATUS_DRDY
Data is ready in the receive holding register.
PARC_STATUS_OVR
Overrun error.
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8.
Extra Information for Parallel Capture
8.1.
Acronyms
Below is a table listing the acronyms used in this module, along with their intended meanings.
8.2.
Acronym
Definition
ADC
Analog to Digital Converter
CMOS
Complementary Metal-Oxide-Semiconductor
DMA
Direct Memory Access
DSP
Digital Signal Processor
I/O
Input/Output
LSB
Least Significant Byte
NVIC
Nested Vectored Interrupt Controller
PCCK
Parallel Capture Clock
PDCA
Peripheral DMA Controller
RHR
Receive Holding Register
QSG
Quick Start Guide
Dependencies
This driver has the following dependencies:
•
8.3.
None
Errata
There are no errata related to this driver.
8.4.
Module History
An overview of the module history is presented in the table below, with details on the enhancements and
fixes made to the module since its first release. The current version of this corresponds to the newest
version in the table.
Changelog
Initial document release
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Atmel-42297B-SAM4L-Parallel-Capture-PARC-Driver_AT07912_Application Note-07/2015
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9.
Examples for Parallel Capture
This is a list of the available Quick Start Guides (QSGs) and example applications for SAM4L Parallel
Capture (PARC) Driver. QSGs are simple examples with step-by-step instructions to configure and use
this driver in a selection of use cases. Note that a QSG can be compiled as a standalone application or
be added to the user application.
•
•
9.1.
Quick Start Guide for the PARC driver
Parallel Capture (PARC) - Example Using GPIO as Stimuli
Quick Start Guide for the PARC driver
This is the quick start guide for the SAM4L Parallel Capture (PARC) Driver, with step-by-step instructions
on how to configure and use the driver for a specific use case.
The use cases contain several code fragments. The code fragments in the steps for setup can be copied
into a custom initialization function, while the steps for usage can be copied into, e.g. the main application
function.
9.1.1.
Use Cases
•
9.1.2.
PARC Basic Use Case
PARC Basic Use Case
This use case demonstrates how to use the PARC module on SAM4L. In this use case the PARC module
is configured as:
•
Capture every byte
•
Sample the data bus on the rising edge of the PCCK input clock
•
Sample data regardless of the levels of PCEN1 and PCEN2
•
8-bit data width
9.1.3.
Setup Steps
9.1.3.1.
Prerequisites
This module requires the following service:
•
System clock (sysclk)
9.1.3.2.
Setup Code Example
Add the following to the main loop or a setup function:
struct parc_module module_inst;
struct parc_config config;
// Get default configuration
parc_get_config_defaults(&config);
// Initialize PARC.
parc_init(&module_inst, PARC, &config);
// Enable the PARC
parc_enable(&module_inst);
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// Start capture.
parc_start_capture(&module_inst);
9.1.3.3.
Basic Setup Workflow
1.
Initialize and configure PARC:
// Get default configuration
parc_get_config_defaults(&config);
// Initialize PARC.
parc_init(&module_inst, PARC, &config);
2.
Enable the PARC module and start capture:
// Enable the PARC
parc_enable(&module_inst);
// Start capture.
parc_start_capture(&module_inst);
9.1.4.
PARC Basic Usage
9.1.4.1.
Basic Usage Code
We can poll the data ready status and then read it once capture has finished:
uint32_t captured_data;
while (!parc_is_data_ready(&module_inst)) {
}
parc_read(&module_inst, &captured_data);
We can enable the data ready interrupt and install a callback function to perform a custom task:
parc_register_callback(&module_inst,
(parc_callback_t)parc_complete_callback, PARC_CALLBACK_DATA_READY);
parc_enable_interrupts(&module_inst, PARC_INTERRUPT_DRDY);
parc_enable_callback(&module_inst, PARC_CALLBACK_DATA_READY);
parc_start_capture(&module_inst);
// The callback function example.
static void parc_complete_callback(
struct parc_module *const module)
{
callback_data_ready = true;
parc_read(module, &captured_data);
}
9.2.
Parallel Capture (PARC) - Example Using GPIO as Stimuli
9.2.1.
Purpose
This example demonstrates the data capture function provided by the PARC module.
9.2.2.
Requirements
This example can be used with the following evaluation kits with PARC and PDCA modules:
Atmel AT07912: SAM4L Parallel Capture (PARC) Driver [APPLICATION NOTE]
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•
•
9.2.3.
SAM4L Xplained Pro
SAM4L8 Xplained Pro
Description
In this example the GPIO pins on the same evaluation board act as the signal source which provides the
PARC module with data, clock, and EN signals.
The GPIO pins should be connected to the PARC pins through the development kit's on-board
connectors. These pins can be connected easily by using interconnect wires on the SAM4L Xplained Pro
and SAM4L8 Xplained Pro evaluation kits.
The connection list on SAM4L Xplained Pro or SAM4L8 Xplained Pro is shown in Figure 9-1 Description
on page 25.
Figure 9-1 Description
EXT3-P9 (PIN_PA06)
EXT3-P15 (PCCK)
EXT1-P7 (PIN_PC00)
EXT3-P8 (PCDATA0)
EXT1-P8 (PIN_PC01)
EXT3-P10(PCDATA1)
EXT1-P6 (PIN_PC02)
EXT4-P15(PCDATA2)
EXT1-P15(PIN_PC03)
EXT4-P7 (PCDATA3)
EXT2-P7 (PIN_PC04)
EXT4-P8 (PCDATA4)
EXT2-P8 (PIN_PC05)
EXT4-P10(PCDATA6)
EXT2-P9 (PIN_PC06)
EXT4-P9 (PCDATA7)
EXT4-P5 (PIN_PC17)
EXT4-P18(PCEN1)
EXT4-P6 (PIN_PC18)
EXT4-P17(PCEN2)
Note: The PCDATA5 signal is only connected to the LCD connector (EXT5) which cannot be connected
to easily using interconnect wires. In this example PCDATA5 is not required so can be left unconnected.
9.2.4.
Main Files
•
•
•
9.2.5.
parc.c: Parallel Capture driver
parc.h: Parallel Capture driver header file
parc_example.c: Parallel Capture example application
Compilation Information
®
®
This software is written for GNU GCC and IAR Embedded Workbench for Atmel . Other compilers may
or may not work.
9.2.6.
Usage
1.
2.
3.
Connect the GPIO pins and PARC port according to the above connection list.
Build the program and download it into the evaluation kit.
®
On the computer, open and configure a terminal application (e.g., HyperTerminal on Microsoft
®
Windows ) with these settings:
•
115200 baud
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4.
5.
•
8 bits of data
•
No parity
•
1 stop bit
•
No flow control
Start the application.
In the terminal window, the following text should appear:
-- SAM PARC Example --- xxxxxx-xx
-- Compiled: xxx xx xxxx xx:xx:xx --
6.
Select the PARC configuration by inputing 'y' or 'n' when the following information is displayed on
the terminal:
Press y to sample the data when both data enable pins are enabled.
Press n to sample the data, don't care the status of the data enable
pins.
Press y to sample all the data.
Press n to sample the data only one out of two.
7.
PARC captures data and sends the captured data to the terminal.
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10.
Document Revision History
Doc. Rev.
Date
Comments
42297B
07/2015
Updated title of application note and added list of supported devices
42297A
05/2014
Initial document release
Atmel AT07912: SAM4L Parallel Capture (PARC) Driver [APPLICATION NOTE]
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