ft245_io.c

/*! \file ft245.c \brief FTDI FT245 USB Inferface Driver Library. */
//*****************************************************************************
//
// File Name    : 'ft245.c'
// Title        : FTDI FT245 USB Inferface Driver Library
// Author       : Pascal Stang - Copyright (C) 2004
// Created      : 2004.02.10
// Revised      : 2004.02.19
// Version      : 0.1
// Target MCU   : Atmel AVR Series
// Editor Tabs  : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested.  Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

#include "lpc2000.h"
//#include <avr/io.h>
//#include <avr/signal.h>
//#include <avr/interrupt.h>

#include "global.h"
#include "timer.h"
#include "membus.h"
#include "ft245.h"

// global variables
static char ft245RxData[FT245_RX_BUFFER_SIZE];
cBuffer ft245RxBuffer;

// Functions
void ft245Init(void)
{
#ifdef FT245_PORT_INTERFACE
    // initialize port pins
    // configure input pins
    cbi(FT245_CTRL_DDR, FT245_TXE);
    cbi(FT245_CTRL_DDR, FT245_RXF);
    //cbi(FT245_CTRL_DDR, FT245_SUSPEND);
    // use pullups
    sbi(FT245_CTRL_PORT, FT245_TXE);
    sbi(FT245_CTRL_PORT, FT245_RXF);
    //sbi(FT245_CTRL_PORT, FT245_SUSPEND);

    // configure output pins
    sbi(FT245_CTRL_DDR, FT245_RESET);
    sbi(FT245_CTRL_DDR, FT245_WR);
    sbi(FT245_CTRL_DDR, FT245_RD);
    // preset the outputs
    sbi(FT245_CTRL_PORT, FT245_RESET);
    cbi(FT245_CTRL_PORT, FT245_WR);
    sbi(FT245_CTRL_PORT, FT245_RD);

    // configure data bus
    outb(FT245_DATA_DDR, 0x00);
    outb(FT245_DATA_PORT, 0xFF);
#endif
#ifdef FT245_MEMBUS_INTERFACE
    // initialize the memory bus
    membusInit();
    // configure status pins
    IODIR &= FT245_TXE;
    IODIR &= FT245_RXF;
#endif
    // initialize the RX buffer
    bufferInit(&ft245RxBuffer, ft245RxData, FT245_RX_BUFFER_SIZE);

    // reset the FT245
    //ft245Reset();

}

void ft245Reset(void)
{
#ifdef FT245_PORT_INTERFACE
    // activate reset line
    cbi(FT245_CTRL_PORT, FT245_RESET);
    // hold for 1ms
    timerPause(1);
    // release reset
    sbi(FT245_CTRL_PORT, FT245_RESET);
#endif
#ifdef FT245_MEMBUS_INTERFACE

#endif
}

u08 ft245ReadByte(void)
{
#ifdef FT245_PORT_INTERFACE
    u08 data;
    // data bus set for input
    outb(FT245_DATA_DDR, 0x00);
    // assert RD line
    cbi(FT245_CTRL_PORT, FT245_RD);
    // wait
    asm volatile ("nop");
    asm volatile ("nop");
    asm volatile ("nop");
    asm volatile ("nop");
    // read data
    data = inb(FT245_DATA_PORTIN);
    // release RD line
    sbi(FT245_CTRL_PORT, FT245_RD);
    // return data
    return data;
#endif
#ifdef FT245_MEMBUS_INTERFACE
    return membusRead(FT245_BASE_ADDRESS);
#endif
}

void ft245WriteByte(u08 data)
{
#ifdef FT245_PORT_INTERFACE
    // wait for transmit fifo to be ready
    while(!ft245CheckTxFifo());
    // assert WR line
    sbi(FT245_CTRL_PORT, FT245_WR);
    // data bus set for output
    outb(FT245_DATA_DDR, 0xFF);
    // write data
    outb(FT245_DATA_PORT, data);
    // wait
    asm volatile ("nop");
    asm volatile ("nop");
    asm volatile ("nop");
    asm volatile ("nop");
    // release WR line
    cbi(FT245_CTRL_PORT, FT245_WR);
    // return data bus to input + pullups
    outb(FT245_DATA_DDR, 0x00);
    outb(FT245_DATA_PORT, 0xFF);
#endif
#ifdef FT245_MEMBUS_INTERFACE
    return membusWrite(FT245_BASE_ADDRESS, data);
#endif
}

u08 ft245CheckRxFifo(void)
{
    // check state of RXF line
    // RXF = L  => Data in fifo ready to be read
    // RXF = H  => No data, or not ready
#ifdef FT245_PORT_INTERFACE
    if( inb(FT245_CTRL_PORTIN) & (1<<FT245_RXF) )
        return FALSE;   // no data
    else
        return TRUE;    // data is available
#endif
#ifdef FT245_MEMBUS_INTERFACE
    if(IOPIN & FT245_RXF)
        return FALSE;   // no data
    else
        return TRUE;    // data is available
#endif
}

u08 ft245CheckTxFifo(void)
{
    // check state of TXE line
    // TXE = L  => Tx fifo is ready to be written
    // TXE = H  => Tx fifo full or not ready
#ifdef FT245_PORT_INTERFACE
    if( inb(FT245_CTRL_PORTIN) & (1<<FT245_TXE) )
        return FALSE;   // full or not ready
    else
        return TRUE;    // tx fifo space is available
#endif
#ifdef FT245_MEMBUS_INTERFACE
    if(IOPIN & FT245_TXE)
        return FALSE;   // full or not ready
    else
        return TRUE;    // tx fifo space is available
#endif
}

/*
u08 ft245IsSuspended(void)
{
    // check state of SUSPEND line
    // SUSPEND = L  => Data in fifo ready to be read
    // SUSPEND = H  => No data, or not ready
    if( inb(FT245_CTRL_PORTIN) & (1<<FT245_RXF) )
        return FALSE;   // no data
    else
        return TRUE;    // data is available
}
*/

void ft245SendByte(u08 data)
{
    // wait for FT245 to become ready
    while(!ft245CheckTxFifo());
    // send byte
    ft245WriteByte(data);
}

cBuffer* ft245GetRxBuffer(void)
{
    // since there is an internal buffer in the FT245 chip
    // we don't read in bytes immediately on reception.
    // instead, the FT245 buffer is read in when the 
    // receive buffer is requested

    // read in receive buffer
    while(ft245CheckRxFifo())
    {
        bufferAddToEnd(&ft245RxBuffer, ft245ReadByte());
    }

    return &ft245RxBuffer;
}

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