/******************************************************************************
MRF24WB0M Driver SPI interface routines
Module for Microchip TCP/IP Stack
*******************************************************************************
FileName: WF_Spi.c
Dependencies: TCP/IP Stack header files
Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F, PIC32
Compiler: Microchip C32 v1.10b or higher
Microchip C30 v3.22 or higher
Microchip C18 v3.34 or higher
Company: Microchip Technology, Inc.
Software License Agreement
Copyright (C) 2002-2010 Microchip Technology Inc. All rights reserved.
Microchip licenses to you the right to use, modify, copy, and distribute:
(i) the Software when embedded on a Microchip microcontroller or digital
signal controller product ("Device") which is integrated into
Licensee's product; or
(ii) ONLY the Software driver source files ENC28J60.c, ENC28J60.h,
ENCX24J600.c and ENCX24J600.h ported to a non-Microchip device used in
conjunction with a Microchip ethernet controller for the sole purpose
of interfacing with the ethernet controller.
You should refer to the license agreement accompanying this Software for
additional information regarding your rights and obligations.
THE SOFTWARE AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ANY WARRANTY
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
NON-INFRINGEMENT. IN NO EVENT SHALL MICROCHIP BE LIABLE FOR ANY INCIDENTAL,
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA, COST
OF PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES, ANY CLAIMS BY
THIRD PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE THEREOF), ANY CLAIMS
FOR INDEMNITY OR CONTRIBUTION, OR OTHER SIMILAR COSTS, WHETHER ASSERTED ON
THE BASIS OF CONTRACT, TORT (INCLUDING NEGLIGENCE), BREACH OF WARRANTY, OR
OTHERWISE.
Author Date Comment
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Zero G Sep 2008 Initial version
KO 31 Oct 2008 Port to PIC24F and PIC32 for TCP/IP stack v4.52
******************************************************************************/
/*
*********************************************************************************************************
* INCLUDES
*********************************************************************************************************
*/
#include "TCPIP Stack/WFMac.h"
#if defined(WF_CS_TRIS)
/*
*********************************************************************************************************
* DEFINES
*********************************************************************************************************
*/
/* used for assertions */
#ifdef WF_DEBUG
#define WF_MODULE_NUMBER WF_MODULE_WF_SPI
#endif
/* Indicate here if the MRF24WB0M is sharing the SPI bus with another device. For the */
/* Microchip demos only the PIC18 on the PICDEM.net 2 board shares the SPI bus. */
#if defined(__18CXX)
#define SPI_IS_SHARED
#endif
#if defined (SPI_IS_SHARED)
/* SPI context save variables */
static BYTE SPIONSave;
#if defined( __18CXX)
static BYTE SPICON1Save;
static BYTE SPISTATSave;
#elif defined( __C30__ )
static WORD SPICON1Save;
static WORD SPICON2Save;
static WORD SPISTATSave;
#elif defined( __PIC32MX__ )
static DWORD SPICON1Save;
static DWORD SPISTATSave;
#else
#error Cannot define SPI context save variables.
#endif
#endif /* SPI_IS_SHARED */
//============================================================================
// SPI Definitions
//============================================================================
#if defined (__18CXX)
#define ClearSPIDoneFlag() {WF_SPI_IF = 0;}
#define WaitForDataByte() {while(!WF_SPI_IF); WF_SPI_IF = 0;}
#define SPI_ON_BIT (WF_SPICON1bits.SSPEN)
#elif defined(__C30__)
#define ClearSPIDoneFlag()
static inline __attribute__((__always_inline__)) void WaitForDataByte( void )
{
while ((WF_SPISTATbits.SPITBF == 1) || (WF_SPISTATbits.SPIRBF == 0));
}
#define SPI_ON_BIT (WF_SPISTATbits.SPIEN)
#elif defined( __PIC32MX__ )
#define ClearSPIDoneFlag()
static inline __attribute__((__always_inline__)) void WaitForDataByte( void )
{
while (!WF_SPISTATbits.SPITBE || !WF_SPISTATbits.SPIRBF);
}
#define SPI_ON_BIT (WF_SPICON1bits.ON)
#else
#error Determine SPI flag mechanism
#endif
/*
*********************************************************************************************************
* LOCAL FUNCTION PROTOTYPES
*********************************************************************************************************
*/
#if defined (SPI_IS_SHARED)
static void SaveSpiContext(void);
static void RestoreSpiContext(void);
#endif
static void ConfigureSpiMRF24WB0M(void);
/*****************************************************************************
Function:
void WF_SpiInit(void)
Summary:
Initializes the SPI interface to the MRF24WB0M device.
Description:
Configures the SPI interface for communications with the MRF24WB0M.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
This function is called by WFHardwareInit.
*****************************************************************************/
void WF_SpiInit(void)
{
/* disable the spi interrupt */
#if defined( __PIC32MX__ )
WF_SPI_IE_CLEAR = WF_SPI_INT_BITS;
#else
WF_SPI_IE = 0;
#endif
#if defined( __18CXX)
WF_SPI_IP = 0;
#endif
// Set up the SPI module on the PIC for communications with the MRF24WB0M
WF_CS_IO = 1;
WF_CS_TRIS = 0; // Drive SPI MRF24WB0M chip select pin
#if defined( __18CXX)
WF_SCK_TRIS = 0; /* SPI Clock is an output */
WF_SDO_TRIS = 0; /* SPI Data Out is an output */
WF_SDI_TRIS = 1; /* SPI Data In is an input */
#else
// We'll let the module control the pins.
#endif
#if !defined( SPI_IS_SHARED )
ConfigureSpiMRF24WB0M();
#endif
/* clear the completion flag */
ClearSPIDoneFlag();
}
/*
Fsck = Fpb
------------------
2 * (SPIxBRG + 1)
Note that the maximum possible baud rate is
Fpb/2 (SPIXBRG = 0) and the minimum possible baud
rate is FPB /1024.
*/
/*****************************************************************************
Function:
void ConfigureSpiMRF24WB0M(void)
Summary:
Configures the SPI interface to the MRF24WB0M.
Description:
Configures the SPI interface for communications with the MRF24WB0M.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
If the SPI bus is shared with other peripherals this function is called
each time an SPI transaction occurs by WF_SpiEnableChipSelect. Otherwise it
is called once during initialization by WF_SpiInit.
*****************************************************************************/
static void ConfigureSpiMRF24WB0M(void)
{
/*----------------------------------------------------------------*/
/* After we save context, configure SPI for MRF24WB0M communications */
/*----------------------------------------------------------------*/
/* enable the SPI clocks */
/* set as master */
/* clock idles high */
/* ms bit first */
/* 8 bit tranfer length */
/* data changes on falling edge */
/* data is sampled on rising edge */
/* set the clock divider */
#if defined(__18CXX)
WF_SPICON1 = 0x30; // SSPEN bit is set, SPI in master mode, (0x30 is for FOSC/4),
// IDLE state is high level (0x32 is for FOSC/64)
WF_SPISTATbits.CKE = 0; // Transmit data on falling edge of clock
WF_SPISTATbits.SMP = 1; // Input sampled at end? of data output time
#elif defined(__C30__)
WF_SPICON1 = 0x027B; // Fcy Primary prescaler 1:1, secondary prescaler 2:1, CKP=1, CKE=0, SMP=1
WF_SPICON2 = 0x0000;
WF_SPISTAT = 0x8000; // Enable the module
#elif defined( __PIC32MX__ )
WF_SPI_BRG = (GetPeripheralClock()-1ul)/2ul/WF_MAX_SPI_FREQ;
WF_SPICON1 = 0x00000260; // sample at end, data change idle to active, clock idle high, master
WF_SPICON1bits.ON = 1;
#else
#error Configure SPI for the selected processor
#endif
}
/*****************************************************************************
Function:
void WF_SpiEnableChipSelect(void)
Summary:
Enables the MRF24WB0M SPI chip select.
Description:
Enables the MRF24WB0M SPI chip select as part of the sequence of SPI
communications.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
If the SPI bus is shared with other peripherals then the current SPI context
is saved.
*****************************************************************************/
void WF_SpiEnableChipSelect(void)
{
#if defined(__18CXX)
static volatile UINT8 dummy;
#endif
#if defined(SPI_IS_SHARED)
SaveSpiContext();
ConfigureSpiMRF24WB0M();
#endif
/* set Slave Select low (enable SPI chip select on MRF24WB0M) */
WF_CS_IO = 0;
/* clear any pending interrupts */
#if defined(__18CXX)
dummy = WF_SSPBUF;
ClearSPIDoneFlag();
#endif
}
/*****************************************************************************
Function:
void WF_SpiDisableChipSelect(void)
Summary:
Disables the MRF24WB0M SPI chip select.
Description:
Disables the MRF24WB0M SPI chip select as part of the sequence of SPI
communications.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
If the SPI bus is shared with other peripherals then the current SPI context
is restored.
*****************************************************************************/
void WF_SpiDisableChipSelect(void)
{
/* Disable the interrupt */
#if defined( __PIC32MX__ )
WF_SPI_IE_CLEAR = WF_SPI_INT_BITS;
#else
WF_SPI_IE = 0;
#endif
/* set Slave Select high ((disable SPI chip select on MRF24WB0M) */
WF_CS_IO = 1;
#if defined(SPI_IS_SHARED)
RestoreSpiContext();
#endif
}
/*****************************************************************************
Function:
void WFSpiTxRx(void)
Summary:
Transmits and receives SPI bytes
Description:
Transmits and receives N bytes of SPI data.
Precondition:
None
Parameters:
p_txBuf - pointer to SPI tx data
txLen - number of bytes to Tx
p_rxBuf - pointer to where SPI rx data will be stored
rxLen - number of SPI rx bytes caller wants copied to p_rxBuf
Returns:
None
Remarks:
Will clock out the larger of txLen or rxLen, and pad if necessary.
*****************************************************************************/
void WFSpiTxRx(UINT8 *p_txBuf,
UINT16 txLen,
UINT8 *p_rxBuf,
UINT16 rxLen)
{
#if defined(__18CXX)
static UINT16 byteCount; /* avoid local variables in functions called from interrupt routine */
static UINT16 i;
static UINT8 rxTrash;
#else
UINT16 byteCount;
UINT16 i;
UINT8 rxTrash;
#endif
#ifdef WF_DEBUG
/* Cannot communicate with MRF24WB0M when it is in hibernate mode */
{
static UINT8 state; /* avoid local vars in functions called from interrupt */
WF_GetPowerSaveState(&state);
WF_ASSERT(state != WF_PS_HIBERNATE);
}
#endif
/* total number of byte to clock is whichever is larger, txLen or rxLen */
byteCount = (txLen >= rxLen)?txLen:rxLen;
for (i = 0; i < byteCount; ++i)
{
/* if still have bytes to transmit from tx buffer */
if (txLen > 0)
{
WF_SSPBUF = *p_txBuf++;
--txLen;
}
/* else done writing bytes out from tx buffer */
else
{
WF_SSPBUF = 0xff; /* clock out a "don't care" byte */
}
/* wait until tx/rx byte to completely clock out */
WaitForDataByte();
/* if still have bytes to read into rx buffer */
if (rxLen > 0)
{
*p_rxBuf++ = WF_SSPBUF;
--rxLen;
}
/* else done reading bytes into rx buffer */
else
{
rxTrash = WF_SSPBUF; /* read and throw away byte */
}
} /* end for loop */
}
#if defined(__18CXX)
/*****************************************************************************
Function:
void WFSpiTxRx_Rom(void)
Summary:
Transmits and receives SPI bytes
Description:
Specific to the PIC18, transmits bytes from ROM storage and receives SPI data
bytes.
Precondition:
None
Parameters:
p_txBuf - pointer to SPI ROM tx data
txLen - number of bytes to Tx
p_rxBuf - pointer to where SPI rx data will be stored
rxLen - number of SPI rx bytes caller wants copied to p_rxBuf
Returns:
None
Remarks:
Will clock out the larger of txLen or rxLen, and pad if necessary.
*****************************************************************************/
void WFSpiTxRx_Rom(ROM UINT8 *p_txBuf,
UINT16 txLen,
UINT8 *p_rxBuf,
UINT16 rxLen)
{
static UINT16 byteCount; /* avoid local variables in functions called from interrupt routine */
static UINT16 i;
static UINT8 rxTrash;
/* total number of byte to clock is whichever is larger, txLen or rxLen */
byteCount = (txLen >= rxLen)?txLen:rxLen;
for (i = 0; i < byteCount; ++i)
{
/* if still have bytes to transmit from tx buffer */
if (txLen > 0)
{
WF_SSPBUF = *p_txBuf++;
--txLen;
}
/* else done writing bytes out from tx buffer */
else
{
WF_SSPBUF = 0xff; /* clock out a "don't care" byte */
}
// wait until tx/rx byte completely clocked out
WaitForDataByte();
/* if still have bytes to read into rx buffer */
if (rxLen > 0)
{
*p_rxBuf++ = WF_SSPBUF;
--rxLen;
}
/* else done reading bytes into rx buffer */
else
{
rxTrash = WF_SSPBUF; /* read and throw away byte */
}
} /* end for loop */
}
#endif
#if defined (SPI_IS_SHARED)
/*****************************************************************************
Function:
void SaveSpiContext(void)
Summary:
Saves SPI context.
Description:
Saves the SPI context (mainly speed setting) before using the SPI to
access MRF24WB0M. Turn off the SPI module before reconfiguring it.
We only need this function if SPI lines are shared.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
Only called if SPI_IS_SHARED is defined
*****************************************************************************/
static void SaveSpiContext(void)
{
// Save SPI state (clock speed)
SPICON1Save = WF_SPICON1;
#if defined( __C30__ )
SPICON2Save = WF_SPICON2;
#endif
SPISTATSave = WF_SPISTAT;
SPIONSave = SPI_ON_BIT;
SPI_ON_BIT = 0;
}
/*****************************************************************************
Function:
void RestoreSpiContext(void)
Summary:
Restores SPI context.
Description:
Restores the SPI context (mainly speed setting) after using the SPI to
access MRF24WB0M. Turn off the SPI module before reconfiguring it.
We only need this function if SPI lines are shared.
Precondition:
None
Parameters:
None
Returns:
None
Remarks:
Only called if SPI_IS_SHARED is defined
*****************************************************************************/
static void RestoreSpiContext(void)
{
SPI_ON_BIT = 0;
WF_SPICON1 = SPICON1Save;
#if defined( __C30__ )
WF_SPICON2 = SPICON2Save;
#endif
WF_SPISTAT = SPISTATSave;
SPI_ON_BIT = SPIONSave;
}
#endif /* SPI_IS_SHARED */
#else
// dummy func to keep compiler happy when module has no executeable code
void MCHP_Spi_EmptyFunc(void)
{
}
#endif /* WF_CS_TRIS */
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