--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gsm-fw/nucleus/demo/sdc.c	Tue Nov 12 05:35:48 2013 +0000
@@ -0,0 +1,1033 @@
+/**************************************************************************
+*                                                                          
+*               Copyright Mentor Graphics Corporation 2002              
+*                         All Rights Reserved.                          
+*                                                                       
+* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS  
+* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS   
+* SUBJECT TO LICENSE TERMS.                                             
+*                                                                          
+***************************************************************************
+***************************************************************************
+*                                                                          
+* FILE NAME                               VERSION                          
+*                                                                          
+*  sdc.c                        Nucleus PLUS\ARM925\Code Composer 1.14.1 
+*                                                                          
+* DESCRIPTION                                                              
+*                                                                          
+*  This file contains the Serial Driver specific functions.                
+*                                                                          
+* DATA STRUCTURES                                                          
+*                                                                          
+*  SD_PORT *       :   An array of pointers to serial port structures.     
+*                                                                          
+* FUNCTIONS                                                                
+*                                                                          
+*  SDC_Init_Port                                                           
+*  SDC_Date_Ready                                                          
+*  SDC_Put_String                                                          
+*  SDC_LISR                                                                
+*  SDC_Get_Char                                                            
+*  SDC_Put_Char                                                            
+*  SDC_Set_Baud_Rate                                                       
+*                                                                          
+* DEPENDENCIES                                                             
+*                                                                          
+*  nucleus.h                                                               
+*  sd_defs.h                                                               
+*  sd_extr.h                                                               
+*   target.h                                                               
+* protocol.h                                                               
+*  externs.h                                                               
+*      ppp.h    
+*
+* HISTORY                                                               
+*                                                                       
+*         NAME            DATE                    REMARKS               
+*
+*      B. Ronquillo     08-28-2002           Released version 1.14.1    
+****************************************************************************/
+
+#include "nucleus.h"
+#include "sd_defs.h"
+#include "sd_extr.h"
+#include "calirq.h"
+
+#ifdef NU_ENABLE_PPP
+
+#include "net\target.h"
+#include "net\inc\externs.h"
+#include "net\inc\tcp_errs.h"
+#include "ppp\inc\ppp.h"
+
+#endif /* NU_ENABLE_PPP */
+
+extern NU_MEMORY_POOL   System_Memory;
+
+/* Define a small array to hold pointers to the two UART data
+   structures. This is used by the LISR to find the correct
+   data structure for the interrupt being handled. */
+SD_PORT         *SDC_Port_List[SD_MAX_UARTS];
+
+
+/* Define prototypes for functions local to this module. */
+
+    /**************** Begin Port Specific Section **************/
+#ifdef GRAFIX_MOUSE
+extern NU_HISR Mouse_HISR;
+#endif
+    /**************** End Port Specific Section **************/
+
+static  VOID    SDC_Set_Baud_Rate(UINT32, SD_PORT *);
+/***************************************************************************
+* FUNCTION
+*
+*    SDC_Init_Port
+*
+* DESCRIPTION
+*
+*    This function intializes the COM port that will be used for PPP
+*    communications.
+*
+*
+* INPUTS
+*
+*    SD_PORT *     :   device initialization structure.
+*
+* OUTPUTS
+*
+*    STATUS        :   Returns NU_SUCCESS if successful initialization,
+*                      else a negative value is returned.
+*
+****************************************************************************/
+STATUS  SDC_Init_Port(SD_PORT *uart)
+{
+STATUS      status = NU_SUCCESS;
+INT32       int_level,          /* old interrupt level */
+            tInt;
+UINT8       temp_byte;
+UINT32      temp_word, int_val;
+CHAR        sem_name[8];
+static INT  num_ports = 0;
+VOID        (*old_lisr)(INT);   /* old LISR */
+
+#ifdef GRAFIX_MOUSE
+    if ((uart->communication_mode == SERIAL_MODE) ||
+        (uart->communication_mode == SERIAL_MOUSE))
+#else
+    if (uart->communication_mode == SERIAL_MOUSE)
+    {
+        status = NU_INVALID_MOUSE_MODE;
+    }
+    else if (uart->communication_mode == SERIAL_MODE)
+#endif
+
+    {
+    
+        /* Check for max allowed UARTS. */
+        if (num_ports >= SD_MAX_UARTS)
+
+           /* We have already initialized the max allowed UARTS. */
+           status = NU_UART_LIST_FULL;
+    }
+    
+    if (status != NU_SUCCESS)
+        return (status);
+
+    /* Check the supplied parity */
+    else if ((uart->parity != SD_PARITY_NONE) &&
+             (uart->parity != SD_PARITY_EVEN) &&
+             (uart->parity != SD_PARITY_ODD))
+
+        /* The supplied parity is not valid */
+        status = NU_INVALID_PARITY;
+
+    /* Check the supplied number of data bits */
+    else if ((uart->data_bits != SD_DATA_BITS_7) &&
+             (uart->data_bits != SD_DATA_BITS_8))
+
+        /* The supplied data bits value is not valid */
+        status = NU_INVALID_DATA_BITS;
+
+    /* Check the supplied number of stop bits */
+    else if ((uart->stop_bits != SD_STOP_BITS_1) &&
+             (uart->stop_bits != SD_STOP_BITS_2))
+
+        /* The supplied stop bits value is not valid */
+        status = NU_INVALID_STOP_BITS;
+
+    /* Verify the baud rate is within acceptable range */
+    else if ((uart->baud_rate < 300) || (uart->baud_rate > 115200))
+
+        /* The baud rate is out of range */
+        status = NU_INVALID_BAUD;
+
+    /************** Begin Port Specific Section ****************/
+
+    /* Validate the com port. */
+    else if ((uart->com_port == SD_UART1) ||
+             (uart->com_port == SD_UART2))
+    {
+        /* Handle UARTA */
+        if (uart->com_port == SD_UART_MODEM)
+        {
+            /* Set the vector inside this structure */
+            uart->vector = IRQ_UART_MODEM;
+
+            /* Set the base address for this UART. */
+            uart->base_address = SD_UART_MODEM_BASE;
+        }
+        else    /* Otherwise handle UARTB. */
+        {
+            /* Set the vector inside this structure */
+            uart->vector = IRQ_UART_IRDA;
+            
+            /* Set the base address for this UART. */
+            uart->base_address = SD_UART_IRDA_BASE;
+        }
+    }
+    else
+
+    /************** End Port Specific Section **************/
+
+        /* Not a supported port. */
+        status = NU_INVALID_COM_PORT;
+
+#ifdef GRAFIX_MOUSE
+    if ((uart->communication_mode == SERIAL_MODE) ||
+        (uart->communication_mode == SERIAL_MOUSE))
+#else
+    if (uart->communication_mode == SERIAL_MODE)
+#endif
+
+    {
+        /* Make sure the port was valid and the LISR was
+           registered. Then create the semaphore used to make
+           the SD_Put_String service thread safe. */
+        if (status == NU_SUCCESS)
+        {
+            /* Allocate memory for the semaphore control block. */
+           status = NU_Allocate_Memory(&System_Memory,(VOID**) &uart->sd_semaphore,
+                        sizeof(NU_SEMAPHORE), NU_NO_SUSPEND);
+
+#if 0
+/* original code */
+            for(tInt=0; tInt < sizeof(NU_SEMAPHORE); tInt++)
+                       /* Fixed SPR 211.  Changed type from (UINT32) to (CHAR *) */
+                       SD_OUTBYTE((CHAR *) uart->sd_semaphore + tInt, 0x00);
+#else
+	    bzero(uart->sd_semaphore, sizeof(NU_SEMAPHORE));
+#endif
+
+            if (status == NU_SUCCESS)
+            {
+                /* Build the name. */
+                sem_name[0] = 's';
+                sem_name[1] = 'e';
+                sem_name[2] = 'r';
+                sem_name[3] = 'i';
+                sem_name[4] = 'a';
+                sem_name[5] = 'l';
+                sem_name[6] = '_';
+                sem_name[7] = (CHAR)(0x30 + num_ports);
+
+                status = NU_Create_Semaphore (uart->sd_semaphore, sem_name,
+                                              1, NU_FIFO);
+            }                                   
+        }
+
+        /* Make sure all the above was completed. Then store off this
+           UART stucture and initialize the chip. */
+        if (status == NU_SUCCESS)
+        {
+            SDC_Port_List[num_ports++] = uart;
+        }
+    }
+
+    if (status == NU_SUCCESS)
+    {
+        /* Allocate memory for the data buffers. PPP only requires a TX
+           buffer so the allocation will be a little different for PPP mode. */
+#ifdef GRAFIX_MOUSE
+        if ((uart->communication_mode == SERIAL_MODE) ||
+            (uart->communication_mode == SERIAL_MOUSE))
+#else
+        if (uart->communication_mode == SERIAL_MODE)
+#endif
+
+        {
+            status = NU_Allocate_Memory (&System_Memory,(VOID**) &uart->tx_buffer, 
+                         (2 * uart->sd_buffer_size), NU_NO_SUSPEND);
+
+            /* Set the RX buffer to just past the TX buffer. */
+            uart->rx_buffer = (CHAR *)(uart->tx_buffer + uart->sd_buffer_size);
+        }
+        else
+        {
+            status = NU_Allocate_Memory (&System_Memory,(VOID**) &uart->tx_buffer, 
+                         uart->sd_buffer_size, NU_NO_SUSPEND);
+        }
+
+        if (status == NU_SUCCESS)
+        {
+            /* Setup the RX SD buffer */
+            uart->rx_buffer_read = uart->rx_buffer_write = 0;
+ 
+            uart->rx_buffer_status = NU_BUFFER_EMPTY;
+
+            /* Setup the TX SD buffer */
+            uart->tx_buffer_read = uart->tx_buffer_write = 0;
+            uart->tx_buffer_status = NU_BUFFER_EMPTY;
+        }
+    }
+
+    if (status == NU_SUCCESS)
+    {
+        /* Disable interrupts */
+        int_level = NU_Local_Control_Interrupts(NU_DISABLE_INTERRUPTS);
+
+        /* Initialize the UART */
+
+        /************** Begin Port Specific Section *************/
+
+        /* Configure the Mode Definition Register */
+        /* Set the serial port to UART mode */
+        SD_OUTBYTE(uart->base_address + MDR_OFFSET, MDR_UART_MODE);
+
+        /* Reset the TX/RX FIFOs */
+        SD_OUTBYTE(uart->base_address + FCR_OFFSET, FCR_FIFO_RESET);
+
+        /* Setup baud rate */
+        SDC_Set_Baud_Rate(uart->baud_rate, uart);
+
+        /* Set the modem control register. Set DTR, RTS to output to LOW,
+           and set INT output pin to normal operating mode */ 
+        SD_OUTBYTE (uart->base_address + MCR_OFFSET, (MCR_DTR_LOW | MCR_RTS_LOW)); 
+
+        /* Setup parity, data bits, and stop bits */
+        SD_OUTBYTE (uart->base_address + LCR_OFFSET,
+                          (LCR_NO_BREAK|uart->parity|uart->data_bits|uart->stop_bits ));
+
+        /* Setup Fifo trigger level and enable FIFO */
+        SD_OUTBYTE (uart->base_address + FCR_OFFSET, 0);
+
+        /* Register the interrupt handler for the UART receiver */
+        status = NU_Register_LISR(uart->vector, SDC_LISR, &old_lisr);
+
+        if (status == NU_SUCCESS)
+        {
+            /* Enable the RX interrupts */
+            SD_OUTBYTE (uart->base_address + IER_OFFSET, IER_RX_HOLDING_REG);
+
+            if(uart->com_port == SD_UART_MODEM)
+            {
+                /* Enable the UART interrupt globally */
+		INTH_REGS.ilr_irq[IRQ_UART_MODEM] = 0x7C;
+		INTH_REGS.mask_it_reg1 &= ~(1 << IRQ_UART_MODEM);
+            }
+            else  /* Handle UART B */
+            {    
+                /* Enable the UART interrupt globally */
+		INTH_REGS.ilr_irq[IRQ_UART_IRDA] = 0x7C;
+		INTH_REGS.mask_it_reg2 &= ~(1 << (IRQ_UART_IRDA - 16));
+            }
+
+        }
+
+        /************** End Port Specific Section *************/
+
+
+        /* Initialize the error counters. */
+        uart->parity_errors   =
+        uart->frame_errors    =
+        uart->overrun_errors  = 
+        uart->busy_errors     = 
+        uart->general_errors  = 0;
+
+        /* Restore interrupts to previous level */
+        NU_Local_Control_Interrupts(int_level);
+    }
+
+    return (status);
+}
+/***************************************************************************
+* FUNCTION
+*
+*    SDC_Put_Char
+*
+* DESCRIPTION
+*
+*    This writes a character out to the serial port.
+*
+* INPUTS
+*
+*    UINT8 :   Character to to be written to the serial port.
+*    SD_PORT *     :   Serial port to send the char to.
+*
+* OUTPUTS
+*
+*    none
+*
+****************************************************************************/
+VOID  SDC_Put_Char(UINT8 ch, SD_PORT *uart)
+{
+INT         int_level;          /* old interrupt level */
+UINT32  temp_long;
+
+#ifdef GRAFIX_MOUSE
+    if ((uart->communication_mode == SERIAL_MODE) ||
+        (uart->communication_mode == SERIAL_MOUSE))
+#else
+    if (uart->communication_mode == SERIAL_MODE)
+#endif
+
+    {
+        /* If the buffer is full wait for it to empty a little. */
+        while (uart->tx_buffer_status == NU_BUFFER_FULL);
+
+        /* Disable interrupts */
+        int_level = NU_Local_Control_Interrupts(NU_DISABLE_INTERRUPTS);
+
+        /* Check the transmit buffer status. If it has data already
+           just add this byte to the buffer. */
+         if ( uart->tx_buffer_status != NU_BUFFER_EMPTY)
+        {
+            /* Add byte to buffer. */
+            uart->tx_buffer[uart->tx_buffer_write++] = ch;
+
+            /* Check for wrap of buffer. */
+            if(uart->tx_buffer_write == uart->sd_buffer_size)
+                uart->tx_buffer_write = 0;
+          
+            /* Check for full buffer. */
+            if (uart->tx_buffer_write == uart->tx_buffer_read) 
+                uart->tx_buffer_status = NU_BUFFER_FULL;
+
+            /* Restore interrupts to previous level */
+            NU_Local_Control_Interrupts(int_level);
+        }
+        else
+        {
+            /* Otherwise send the data. */
+
+            /* Restore interrupts to previous level */
+            NU_Local_Control_Interrupts(int_level);
+
+            /* Add byte to buffer. */
+            uart->tx_buffer[uart->tx_buffer_write++] = ch;
+
+            /* Check for wrap of buffer. */
+            if(uart->tx_buffer_write == uart->sd_buffer_size)
+                uart->tx_buffer_write = 0;
+             
+            /* Set status */
+            uart->tx_buffer_status = NU_BUFFER_DATA;
+
+            /**************** Begin Port Specific Section **************/
+
+            /* Wait until the transmitter buffer is empty */
+            while (!(SD_INBYTE (uart->base_address + LSR_OFFSET) & LSR_TX_HOLD_EMPTY));
+
+            /* Transmit the character */
+            SD_OUTBYTE (uart->base_address + THR_OFFSET, ch);
+
+            /* Enable the TX interrupts */
+            temp_long = SD_INBYTE (uart->base_address + IER_OFFSET);
+            temp_long |= IER_TX_HOLDING_REG;
+            SD_OUTBYTE (uart->base_address + IER_OFFSET, temp_long);               
+
+        }
+    
+    }  /* endif mode */
+    else 
+    {
+        /* Wait until the transmitter buffer is empty */
+        while (!(SD_INBYTE (uart->base_address + LSR_OFFSET) & LSR_TX_HOLD_EMPTY));
+
+        /* Transmit the character */
+          SD_OUTBYTE (uart->base_address + THR_OFFSET, ch);
+
+#ifndef PPP_POLLED_TX
+
+            /* Enable the TX interrupts */
+            temp_long = SD_INBYTE (uart->base_address + IER_OFFSET);
+            temp_long |= IER_TX_HOLDING_REG;
+            SD_OUTBYTE (uart->base_address + IER_OFFSET, temp_long);
+                 
+#endif /* PPP_POLLED_TX */
+
+
+    }
+
+        /***************** End Port Specific Section ***************/
+
+}
+
+/***************************************************************************
+* FUNCTION
+*
+*    SDC_LISR
+*
+* DESCRIPTION
+*
+*    This is the entry function for the receive ISR that services the UART
+*    in the ARM925.
+*
+* INPUTS
+*
+*    INT         :   Interrupt vector
+*
+* OUTPUTS
+*
+*    none
+*
+****************************************************************************/
+VOID  SDC_LISR(INT vector)
+{
+
+SD_PORT         *uart;
+CHAR            receive;
+UINT8           status;
+UINT8           int_status;
+UINT8           vector_found = NU_FALSE;
+UINT8           ier_val;
+
+
+#ifdef NU_ENABLE_PPP
+DV_DEVICE_ENTRY *device;
+#endif /* NU_ENABLE_PPP */
+
+    for(receive = 0 ; (SDC_Port_List[receive] != NU_NULL) &&
+        (receive < SD_MAX_UARTS) && !vector_found ; receive++)
+    {
+        /* See if we found one. Better have since we got an interrupt
+           from one. */
+        if (SDC_Port_List[receive] -> vector == vector)
+        {
+            /* Point our local structure to it. */
+            uart = SDC_Port_List[receive];
+            vector_found = NU_TRUE;
+        }
+    }
+
+#ifdef  NU_ENABLE_PPP
+
+    /* Find the device for this interrupt */
+    if ( (device = DEV_Get_Dev_For_Vector(vector)) != NU_NULL)
+    {
+        /* Get the address of the uart structure for this device. */ 
+        uart = &((PPP_LAYER *) device->ppp_layer)->uart;
+        vector_found = NU_TRUE;    
+    }
+
+#endif /* NU_ENABLE_PPP */
+    
+    if (vector_found == NU_TRUE)
+    {
+        /**************** Begin Port Specific Section **************/
+
+        /* Get the interrupt status register value */
+        int_status = SD_INBYTE(uart->base_address + IIR_OFFSET);
+
+        /* Loop until all interrupts are processed */
+        while (!(int_status & IIR_PENDING))
+        {
+            /* Check for a receive interrupt */
+            if (((int_status & IIR_RX_LINE_STAT) ==IIR_RX_LINE_STAT) ||
+                ((int_status & IIR_RX_RDY) ==IIR_RX_RDY) ||
+                ((int_status & IIR_RX_TIMEOUT) ==IIR_RX_TIMEOUT) )
+            {
+               /* Process every character in the receive FIFO */
+                status = SD_INBYTE(uart->base_address + LSR_OFFSET);
+
+                while (status & LSR_RX_DATA_READY)
+                {
+                    /* Get character from receive FIFO */
+                    receive = SD_INBYTE (uart->base_address + RHR_OFFSET);
+
+                    /* Check if receive character has errors */
+                    if (status & (LSR_FRAMING_ERROR | LSR_PARITY_ERROR))
+                    {
+                        /* Increment parity errors if necessary */
+                        uart->parity_errors += ((status & LSR_PARITY_ERROR) == LSR_PARITY_ERROR);
+
+                        /* Increment framing errors if necessary */
+                        uart->frame_errors += ((status & LSR_FRAMING_ERROR) == LSR_FRAMING_ERROR);
+                    }
+                    else    // no framing or parity errors
+                    {
+                        /* Increment overrun errors if necessary */
+                        uart->overrun_errors += ((status & LSR_RX_DATA_READY) == LSR_RX_DATA_READY);
+
+                        /* Switch based on UART mode */
+                        switch(uart->communication_mode)
+                        {
+                            case SERIAL_MODE: 
+
+                                if (uart->rx_buffer_status != NU_BUFFER_FULL)
+                                {
+                
+                                    /* Put the character into the buffer */
+                                    uart->rx_buffer[uart->rx_buffer_write++] = receive;
+
+                                    /* Check for wrap of buffer. */
+                                    if(uart->rx_buffer_write == uart->sd_buffer_size)
+                                        uart->rx_buffer_write = 0;
+                                    
+                                    /* Set status field based on latest character */
+                                    if (uart->rx_buffer_write == uart->rx_buffer_read)
+                                        uart->rx_buffer_status = NU_BUFFER_FULL;
+                                    else
+                                        uart->rx_buffer_status = NU_BUFFER_DATA;
+                                }
+                                else
+                                    uart->busy_errors++;
+
+                            break;
+                    
+#ifdef NU_ENABLE_PPP
+                            /* call PPP processing functions */
+
+                            case MDM_NETWORK_COMMUNICATION:
+                                /* Call this devices receive routine */
+                                device->dev_receive(device);
+                            break;
+
+                            case MDM_TERMINAL_COMMUNICATION:
+                            default:
+                                MDM_Receive(device);
+                            break;
+#endif /* NU_ENABLE_PPP */
+                        } 
+                    }
+
+                    /* Check the rx buffer status again... */
+                    status = SD_INBYTE(uart->base_address + LSR_OFFSET);
+
+                }
+
+            }   // if ((status & IIR_TYPE_MASK) == IIR_Rx_Rdy)
+
+
+            int_status = SD_INBYTE(uart->base_address + IER_OFFSET);
+
+            if (int_status & IER_TX_HOLDING_REG)
+            {
+               if (uart->communication_mode == SERIAL_MODE)
+                {    
+                    /* Bump the read pointer past the byte that was just
+                       transmitted. */
+                    ++(uart->tx_buffer_read);
+                
+                    /* Check for wrap of buffer. */
+                    if(uart->tx_buffer_read == uart->sd_buffer_size)
+                        uart->tx_buffer_read = 0;
+
+                    /* Update the status. */
+                    if (uart->tx_buffer_write == uart->tx_buffer_read)
+                    {
+                       uart->tx_buffer_status = NU_BUFFER_EMPTY;
+
+                        /* Since it is now empty disable the TX interrupt! */
+                        ier_val =  SD_INBYTE(uart->base_address + IER_OFFSET);
+                        ier_val &= ~IER_TX_HOLDING_REG;
+                        SD_OUTBYTE(uart->base_address + IER_OFFSET, ier_val);
+                    }
+                    else
+                    {
+
+                        /* Wait until the transmitter buffer is empty */
+                        while (!(SD_INBYTE (uart->base_address + LSR_OFFSET) & LSR_TX_HOLD_EMPTY));
+
+                        /* Send the next byte in the queue. */
+                        SD_OUTBYTE(uart->base_address + THR_OFFSET, uart->tx_buffer[uart->tx_buffer_read]);
+                        
+                        /* Update the status. */
+                        uart->tx_buffer_status = NU_BUFFER_DATA;
+                    }
+                }
+#ifdef NU_ENABLE_PPP
+               else
+                {
+#ifndef PPP_POLLED_TX
+                   /* Check for a transmit interrupt. */
+                   /* Is there another byte in the TX buffer to send? */
+                   if (uart->tx_buffer_read != uart->tx_buffer_write)
+                   {
+                        /* Wait until the transmitter buffer is empty */
+                        while (!(SD_INBYTE (uart->base_address + LSR_OFFSET) & LSR_TX_HOLD_EMPTY));
+
+                        /* Send the next byte in the queue. */
+                        SD_OUTBYTE (uart->base_address + THR_OFFSET, uart->tx_buffer[uart->tx_buffer_read++]); 
+                        
+                        /* Check for wrap of buffer. */
+                        uart->tx_buffer_read %= uart->sd_buffer_size;
+                   }
+                   else
+                   {
+                   
+                        /* Since it is now empty disable the TX interrupt! */
+                        ier_val =  SD_INBYTE (uart->base_address + IER_OFFSET);
+                        ier_val &= ~IER_TX_HOLDING_REG;
+                        SD_OUTBYTE (uart->base_address + IER_OFFSET, ier_val);
+
+                       /* Only activate the HISR if we are tranmitting
+                          network data. */
+                       if (uart->communication_mode == MDM_NETWORK_COMMUNICATION)
+                       {
+                            /* Add this device to the list of PPP devices that have finished
+                               sending a packet. */
+                            _ppp_tx_dev_ptr_queue [_ppp_tx_dev_ptr_queue_write++] = device;
+
+                            /* Activate the HISR that will take care of processing the
+                               next packet in queue, if one is ready. */
+                            NU_Activate_HISR (&PPP_TX_HISR);
+
+                            /* Check for wrap of ring buffer. */
+                
+                            _ppp_tx_dev_ptr_queue_write %= PPP_MAX_TX_QUEUE_PTRS;
+
+                       }
+                    }
+#endif /* PPP_POLLED_TX */
+                }
+#endif /* NU_ENABLE_PPP */
+            }
+
+            /* Get the interrupt status register value */
+            int_status = SD_INBYTE(uart->base_address + IIR_OFFSET);
+        }
+        
+        /**************** End Port Specific Section **************/
+    
+        /* No port is associated with the vector */
+    }
+    else 
+    {
+        ERC_System_Error(NU_UNHANDLED_INTERRUPT);
+    }   
+}
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Set_Baud_Rate
+*
+* DESCRIPTION
+*
+*    This function sets the UART buad rate.
+*
+* INPUTS
+*
+*    UINT32      :  The new baud rate.
+*    SD_PORT *     :  Serial port to set the baud rate.
+*
+* OUTPUTS
+*
+*    none
+*
+****************************************************************************/
+VOID  SDC_Set_Baud_Rate(UINT32 baud_rate, SD_PORT *uart)
+{
+    UNSIGNED    baud_div;
+    UINT32      temp_long;
+
+    /**************** Begin Port Specific Section **************/
+
+    /* Write to the divisor latch bit to enable the DLH and DLL registers */
+    temp_long = SD_INBYTE(uart->base_address + LCR_OFFSET);
+    SD_OUTBYTE (uart->base_address + LCR_OFFSET, LCR_DIV_EN);             
+
+    /* Set the baud rate */
+    baud_div = 115200 * 7 / uart->baud_rate;
+
+    /* Put LSB in DLL Reg */
+    SD_OUTBYTE (uart->base_address + DLL_OFFSET, baud_div);
+
+    /* Put MSB in DLH Reg */    
+    SD_OUTBYTE (uart->base_address + DLH_OFFSET, (baud_div >> 8));
+
+    /* Disable the Divisor Latch bit */
+    SD_OUTBYTE (uart->base_address + LCR_OFFSET, temp_long & ~LCR_DIV_EN);             
+   /**************** End Port Specific Section ****************/
+
+}
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Get_Char
+*
+* DESCRIPTION
+*
+*    This function reads the last received character from the UART.
+*
+* INPUTS
+*
+*    SD_PORT *      :   Serial port to get the char from.
+*
+* OUTPUTS
+*
+*    CHAR  :  Character read
+*
+****************************************************************************/
+CHAR  SDC_Get_Char(SD_PORT *uart)
+{
+    CHAR    ch = NU_NULL;
+
+#ifdef GRAFIX_MOUSE
+    if ((uart->communication_mode == SERIAL_MODE) ||
+        (uart->communication_mode == SERIAL_MOUSE))
+#else
+    if (uart->communication_mode == SERIAL_MODE)
+#endif
+
+    {
+        if ((uart->rx_buffer_status == NU_BUFFER_FULL) ||
+            (uart->rx_buffer_status == NU_BUFFER_DATA))
+        {
+            /* Store the character to be returned */
+            ch = uart->rx_buffer[uart->rx_buffer_read++]; 
+
+            /* If read pointer is at end, wrap it around */
+            if (uart->rx_buffer_read == uart->sd_buffer_size)
+                uart->rx_buffer_read = 0;
+
+            /* Set the status to reflect removal of the character */
+            if (uart->rx_buffer_write == uart->rx_buffer_read)
+                uart->rx_buffer_status = NU_BUFFER_EMPTY;
+            else
+                uart->rx_buffer_status = NU_BUFFER_DATA;
+        }
+
+        return (ch);
+    } /* endif mode */
+
+#ifdef NU_ENABLE_PPP
+    else if (uart->communication_mode == MDM_TERMINAL_COMMUNICATION || 
+             uart->communication_mode == MDM_NETWORK_COMMUNICATION)
+
+    /**************** Begin Port Specific Section **************/
+
+             return ((UINT8)SD_INBYTE (uart->base_address + RHR_OFFSET));
+
+    /**************** End Port Specific Section ****************/
+
+#endif /* NU_ENABLE_PPP */
+
+    /* Execution should never reach this point, this return was added
+       in response to the 'implicit return' compiler warning */
+
+    return (ch);
+}
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Carrier
+*
+* DESCRIPTION
+*
+*    This function checks for a carrier.
+*
+* INPUTS
+*
+*    none
+*
+* OUTPUTS
+*
+*    STATUS    :  The status of the detection.
+*
+****************************************************************************/
+STATUS SDC_Carrier(SD_PORT *uart)
+{
+    return (NU_TRUE);
+}
+
+/****************************************************************************
+ Note: All functions below this point are generic and should not require
+       any changes to support other UARTS.
+ ****************************************************************************/
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Put_String
+*
+* DESCRIPTION
+*
+*    This writes a null-terminated string out to the serial port.
+*
+* INPUTS
+*
+*    CHAR *        :   String to be written to the serial port.
+*    SD_PORT *     :   Serial port to send the string to.
+*
+* OUTPUTS
+*
+*    none
+*
+****************************************************************************/
+VOID SDC_Put_String(CHAR *str, SD_PORT *uart)
+{
+
+   /* Grab the semaphore so that strings between threads
+       do not get mixed. */
+    if (NU_Obtain_Semaphore(uart->sd_semaphore, NU_SUSPEND) == NU_SUCCESS)
+    {
+
+        /* Send out the string. */
+        for (; *str != 0; str++)
+            SDC_Put_Char(*str, uart);
+
+        /* Allow other threads to use this service. */
+        NU_Release_Semaphore (uart->sd_semaphore);
+    }
+
+}
+
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Data_Ready
+*
+* DESCRIPTION
+*
+*    This function checks to see if there are any characters in the
+*    receive buffer.  A status value is returned indicating whether
+*    characters are present in the receive buffer.
+*
+* INPUTS
+*
+*    SD_PORT *      :   Serial port to check for data.
+*
+* OUTPUTS
+*
+*    STATUS                                The status indicates the
+*                                          presence of characters.
+*
+****************************************************************************/
+STATUS SDC_Data_Ready(SD_PORT *port)
+{
+    /* Check the status. */
+    if((port->rx_buffer_status == NU_BUFFER_FULL) ||
+       (port->rx_buffer_status == NU_BUFFER_DATA))
+
+        return (NU_TRUE);
+
+    else
+
+        return (NU_FALSE);
+}
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Change_Communication_Mode
+*
+* DESCRIPTION
+*
+*    This function switches the serial port between terminal mode and
+*    network mode.  The mode affects how incoming characters are directed.
+*
+* INPUTS
+*
+*    INT      :  The mode of operation desired.
+*
+* OUTPUTS
+*
+*    none
+*
+****************************************************************************/
+VOID SDC_Change_Communication_Mode(INT mode, SD_PORT *uart)
+{
+    uart->communication_mode = mode;
+
+} /* SDC_Change_Communication_Mode */
+
+/****************************************************************************
+* FUNCTION
+*
+*    SDC_Reset
+*
+* DESCRIPTION
+*
+*    This function intializes the data variables associated with a UART
+*
+* INPUTS
+*
+*    SD_PORT      * :   Serial port to reset
+*
+* OUTPUTS
+*
+*    STATUS      :   Returns URT_SUCCESS if successful initialization,
+*                    else a negative value is returned.
+*
+****************************************************************************/
+VOID SDC_Reset (SD_PORT *uart)
+{
+    /* Ini the error counters */
+    uart->frame_errors   = 0;
+    uart->overrun_errors = 0;
+    uart->parity_errors  = 0;
+    uart->busy_errors    = 0;
+    uart->general_errors = 0;
+}
+
+/***************************************************************************
+* FUNCTION
+*
+*    URT_Init_Port
+*
+* DESCRIPTION
+*
+*    This function intializes the data variables associated with a UART
+*
+* INPUTS
+*
+*    SD_PORT      * :   Serial port to reset
+*
+* OUTPUTS
+*
+*    STATUS      :   Returns URT_SUCCESS if successful initialization,
+*                    else a negative value is returned.
+*
+****************************************************************************/
+#ifdef NU_ENABLE_PPP
+STATUS  URT_Init_Port(DV_DEVICE_ENTRY *device)
+{
+    SD_PORT   *uart;
+    STATUS    ret_status;
+
+    /* Get a pointer to the UART layer of this device. */
+    uart = &((PPP_LAYER *) device->ppp_layer)->uart;
+
+    /* Init the serial port, copy init parameters from the device 
+       structure. */
+    uart->com_port              = device->dev_com_port;
+    uart->baud_rate             = device->dev_baud_rate;
+    uart->data_bits             = device->dev_data_bits;
+    uart->stop_bits             = device->dev_stop_bits;
+    uart->parity                = device->dev_parity;
+    uart->data_mode             = device->dev_data_mode;
+    uart->vector                = device->dev_vect;
+    uart->driver_options        = device->dev_driver_options;
+    uart->communication_mode    = MDM_TERMINAL_COMMUNICATION;
+    uart->sd_buffer_size        = (2 * (PPP_MTU + PPP_FCS_SIZE + 
+                                    PPP_MAX_PROTOCOL_SIZE + PPP_MAX_ADDR_CONTROL_SIZE));
+
+    /* Init the port */
+    ret_status = NU_SD_Init_Port (uart);
+
+    if (ret_status == NU_SUCCESS)
+    {
+        /* Copy the vector back into the device entry just in case
+           the UART driver changed it. */
+        device->dev_vect = uart->vector;
+    }
+
+    return (ret_status);
+
+}
+#endif /* NU_ENABLE_PPP */