spi.c

来自「采用mega16设计的avr单片机编程工具」· C语言 代码 · 共 146 行

////////////////////////////////////////////////////////////////////////////////////////////////////
/// @file	spi.c
/// @author	Simon Qian([e-mail])
/// @date	Last Update on 2008-04-07
/// @brief	spi Interface for ISP
/// @par	license
/// 		AVRminiProg is distributed under the terms and conditions of GPLv2, see License.txt
////////////////////////////////////////////////////////////////////////////////////////////////////
#include <avr/io.h>

#include "../../../type.h"
#include "../../../app_cfg.h"

#include "../../../MCU/gpio.h"

#include "../../../Delay/delay.h"

#include "spi.h"

#if AVRP_ISP_SHOULD_ENABLE || AVRP_JTAG_SHOULD_ENABLE

#if AVRP_ISP_SHOULD_ENABLE
uint8 SPI_Emu = 0;
uint8 SPI_Dly;

void SPI_Delay(uint8 dly)
{
	if(dly > 0)
		dly++;
	while(dly--)DelayUS(30);
}

/// Set spi Clock
/// @param[in]	ps		Programming Speed
void SPI_SetClk(uint8 ps)
{
	if(ps > 5)
	{
		SPI_Emu = 1;
		SPI_Dly = (ps >> 4);
		SPI_Disable();
	}
	else
	{
		SPI_Emu = 0;
		SPCR = (1 << SPE) | (1 << MSTR);

		if(ps & 1)
			SPSR = 0;
		else
			SPSR = (1 << SPI2X);
		SPCR &= ~((1 << SPR0) | (1 << SPR1));
		SPCR |= (ps >> 1) + 1;
	}
}

/// spi Read and Write emulated by IO
/// @param[in]	data	data to write
/// @return		data read
uint8 SPI_RW_Emu(uint8 data)
{
	uint8 tmp,ret = 0;

	for(tmp = SPI_DATA_LEN;tmp;tmp--)
	{
		if(data & SPI_MSB)
			SPI_SetMOSI();
		else
			SPI_ClrMOSI();
		data <<= 1;

		SPI_Delay(SPI_Dly);

		SPI_SetSCK();

		SPI_Delay(SPI_Dly);

		ret <<= 1;
		if(SPI_GetMISO())
			ret |= 1;

		SPI_Delay(SPI_Dly);

		SPI_ClrSCK();

		SPI_Delay(SPI_Dly);
	}
	return ret;
}

/// spi Read and Write by spi hardware
/// @param[in]	data	data to write
/// @return		data read
uint8 SPI_RW_HW(uint8 data)
{
	uint8 ret;

	SPI_WaitReady();

	ret =  SPI_GetData();

	SPI_SetData(data);

	return ret;
}

/// spi Read and Write
/// @param[in]	data	data to write
/// @return		data read
uint8 SPI_RW(uint8 data)
{
	uint8 ret;

	if(SPI_Emu)
	{
		ret = SPI_RW_Emu(data);
	}
	else
	{
		SPI_SetData(data);

		SPI_WaitReady();

		ret = SPI_GetData();
	}

	return ret;
}
#endif		// #if AVRP_ISP_SHOULD_ENABLE

/// spi Initialization
/// @return
void SPI_Init(void)
{
#ifdef SPI_SS_Init
	SPI_SS_Init();
#endif

	SPI_ClrSCK();

	SPI_SetSCKOutput();
	SPI_SetMOSIOutput();
	SPI_SetMISOInput();
}
#endif		// #if AVRP_ISP_SHOULD_ENABLE || AVRP_JTAG_SHOULD_ENABLE