Subversion Repositories openrisc

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support 
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: 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
 * 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.
 * ----------------------------------------------------------------------------
 */
 
//------------------------------------------------------------------------------
/// \dir
/// !Purpose
///
/// Set of functions and definition for using a SSC peripheral.
///
/// !Usage
///
/// -# Enable the SSC interface pins (see pio & board.h).
/// -# Configure the SSC to operate at a specific frequency by calling
///    SSC_Configure(). This function enables the peripheral clock of the SSC,
///    but not its PIOs.
/// -# Configure the transmitter and/or the receiver using the
///    SSC_ConfigureTransmitter() and SSC_ConfigureEmitter() functions.
/// -# Enable the PIOs or the transmitter and/or the received.
/// -# Enable the transmitter and/or the receiver using SSC_EnableTransmitter()
///    and SSC_EnableReceiver()
/// -# Send data through the transmitter using SSC_Write() and SSC_WriteBuffer()
/// -# Receive data from the receiver using SSC_Read() and SSC_ReadBuffer()
/// -# Disable the transmitter and/or the receiver using SSC_DisableTransmitter()
///    and SSC_DisableReceiver()
//------------------------------------------------------------------------------
 
#ifndef SSC_H
#define SSC_H
 
//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------
 
#include <board.h>
 
//------------------------------------------------------------------------------
//         Definitions
//------------------------------------------------------------------------------
 
//------------------------------------------------------------------------------
/// \page "SSC configuration macros"
/// This page lists several macros which are used when configuring a SSC
/// peripheral.
/// 
/// !Macros
/// - SSC_STTDLY
/// - SSC_PERIOD
/// - SSC_DATLEN
/// - SSC_DATNB
/// - SSC_FSLEN
 
/// Calculates the value of the STTDLY field given the number of clock cycles
/// before the first bit of a new frame is transmitted.
#define SSC_STTDLY(bits)        (bits << 16)
 
/// Calculates the value of the PERIOD field of the Transmit Clock Mode Register
/// of an SSC interface, given the desired clock divider.
#define SSC_PERIOD(divider)     (((divider / 2) - 1) << 24)
 
/// Calculates the value of the DATLEN field of the Transmit Frame Mode Register
/// of an SSC interface, given the number of bits in one sample.
#define SSC_DATLEN(bits)        (bits - 1)
 
/// Calculates the value of the DATNB field of the Transmit Frame Mode Register
/// of an SSC interface, given the number of samples in one frame.
#define SSC_DATNB(samples)      ((samples -1) << 8)
 
/// Calculates the value of the FSLEN field of the Transmit Frame Mode Register
/// of an SSC interface, given the number of transmit clock periods that the 
/// frame sync signal should take.
#define SSC_FSLEN(periods)      ((periods - 1) << 16)
//------------------------------------------------------------------------------
 
//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------
extern void SSC_Configure(AT91S_SSC *ssc,
                                 unsigned int id,
                                 unsigned int bitRate,
                                 unsigned int masterClock);
extern void SSC_ConfigureTransmitter(AT91S_SSC *ssc,
                                            unsigned int tcmr,
                                            unsigned int tfmr);
extern void SSC_ConfigureReceiver(AT91S_SSC *ssc,
                                         unsigned int rcmr,
                                         unsigned int rfmr);
 
extern void SSC_EnableTransmitter(AT91S_SSC *ssc);
extern void SSC_DisableTransmitter(AT91S_SSC *ssc);
extern void SSC_EnableReceiver(AT91S_SSC *ssc);
extern void SSC_DisableReceiver(AT91S_SSC *ssc);
 
extern void SSC_EnableInterrupts(AT91S_SSC *ssc, unsigned int sources);
extern void SSC_DisableInterrupts(AT91S_SSC *ssc, unsigned int sources);
 
extern void SSC_Write(AT91S_SSC *ssc, unsigned int frame);
extern unsigned char SSC_WriteBuffer(AT91S_SSC *ssc,
                                            void *buffer,
                                            unsigned int length);
extern unsigned int SSC_Read(AT91S_SSC *ssc);
extern unsigned char SSC_ReadBuffer(AT91S_SSC *ssc,
                                           void *buffer,
                                           unsigned int length);
 
#endif //#ifndef SSC_H