quickdev16/poc/lpc2148_efsl/test/uart.c

/******************************************************************************
 *
 * $RCSfile: $
 * $Revision: $
 *
 * This module provides interface routines to the LPC ARM UARTs.
 * Copyright 2004, R O SoftWare
 * No guarantees, warrantees, or promises, implied or otherwise.
 * May be used for hobby or commercial purposes provided copyright
 * notice remains intact.
 *
 * reduced to see what has to be done for minimum UART-support by mthomas
 *****************************************************************************/

// #warning "this is a reduced version of the R O Software code"

#include "lpc214x.h"
#include "uart.h"

/* on LPC210x: UART0 TX-Pin=P0.2, RX-Pin=P0.1 
   PINSEL0 has to be set to "UART-Function" = Function "01" 
   for Pin 0.0 and 0.1 */

#define PINSEL_BITPIN0  0
#define PINSEL_BITPIN1  2
#define PINSEL_BITPIN8  16
#define PINSEL_BITPIN9  18
#define PINSEL_FIRST_ALT_FUNC    1
#define PINSEL_SECOND_ALT_FUNC   2
#define PINSEL_THIRD_ALT_FUNC    3

// Values of Bits 0-3 in PINSEL to activate UART0
#define UART0_PINSEL    ((PINSEL_FIRST_ALT_FUNC<<PINSEL_BITPIN0)|(PINSEL_FIRST_ALT_FUNC<<PINSEL_BITPIN1))
// Mask of Bits 0-4
#define UART0_PINMASK      (0x0000000F) /* PINSEL0 Mask for UART0 */

// Values of Bits 16-19 in PINSEL to activate UART1
#define UART1_PINSEL    ((PINSEL_FIRST_ALT_FUNC<<PINSEL_BITPIN8)|(PINSEL_FIRST_ALT_FUNC<<PINSEL_BITPIN9))
// Mask of Bits 16-19
#define UART1_PINMASK      (0x000F0000) /* PINSEL0 Mask for UART1 */

// U0_LCR devisor latch bit 
#define UART0_LCR_DLAB  7
// U1_LCR devisor latch bit 
#define UART1_LCR_DLAB  7

/*    baudrate divisor - use UART_BAUD macro
 *    mode - see typical modes (uart.h)
 *    fmode - see typical fmodes (uart.h)
 *    NOTE: uart0Init(UART_BAUD(9600), UART_8N1, UART_FIFO_8); 
 */
void uart0Init(uint16_t baud, uint8_t mode, uint8_t fmode)
{

    // setup Pin Function Select Register (Pin Connect Block) 
    // make sure old values of Bits 0-4 are masked out and
    // set them according to UART0-Pin-Selection
    PINSEL0 = (PINSEL0 & ~UART0_PINMASK) | UART0_PINSEL;
    U0IER = 0x00;               // disable all interrupts
    U0IIR = 0x00;               // clear interrupt ID register
    U0LSR = 0x00;               // clear line status register

    // set the baudrate - DLAB must be set to access DLL/DLM
    U0LCR = (1 << UART0_LCR_DLAB);      // set divisor latches (DLAB)
    U0DLL = (uint8_t) baud;     // set for baud low byte
    U0DLM = (uint8_t) (baud >> 8);      // set for baud high byte

    // set the number of characters and other
    // user specified operating parameters
    // Databits, Parity, Stopbits - Settings in Line Control Register
    U0LCR = (mode & ~(1 << UART0_LCR_DLAB));    // clear DLAB "on-the-fly"
    // setup FIFO Control Register (fifo-enabled + xx trig) 
    U0FCR = fmode;
} int uart0Putch(int ch)
{
    while (!(U0LSR & ULSR_THRE))        // wait for TX buffer to empty
        continue;               // also either WDOG() or swap()
    U0THR = (uint8_t) ch;       // put char to Transmit Holding Register
    return (uint8_t) ch;        // return char ("stdio-compatible"?)
}
const char *uart0Puts(const char *string)
{
    char ch;
    while ((ch = *string)) {
        if (uart0Putch(ch) < 0)
            break;
        string++;
    }
    return string;
}
int uart0TxEmpty(void)
{
    return (U0LSR & (ULSR_THRE | ULSR_TEMT)) == (ULSR_THRE | ULSR_TEMT);
}
void uart0TxFlush(void)
{
    U0FCR |= UFCR_TX_FIFO_RESET;        // clear the TX fifo
}

/* Returns: character on success, -1 if no character is available */
int uart0Getch(void)
{
    if (U0LSR & ULSR_RDR)       // check if character is available
        return U0RBR;           // return character
    return -1;
}


/*    baudrate divisor - use UART_BAUD macro
 *    mode - see typical modes (uart.h)
 *    fmode - see typical fmodes (uart.h)
 *    NOTE: uart0Init(UART_BAUD(9600), UART_8N1, UART_FIFO_8); 
 */
void uart1Init(uint16_t baud, uint8_t mode, uint8_t fmode)
{

    // setup Pin Function Select Register (Pin Connect Block) 
    // make sure old values of Bits 0-4 are masked out and
    // set them according to UART0-Pin-Selection
    PINSEL0 = (PINSEL0 & ~UART1_PINMASK) | UART1_PINSEL;
    U1IER = 0x00;               // disable all interrupts
    U1IIR = 0x00;               // clear interrupt ID register
    U1LSR = 0x00;               // clear line status register

    // set the baudrate - DLAB must be set to access DLL/DLM
    U1LCR = (1 << UART1_LCR_DLAB);      // set divisor latches (DLAB)
    U1DLL = (uint8_t) baud;     // set for baud low byte
    U1DLM = (uint8_t) (baud >> 8);      // set for baud high byte

    // set the number of characters and other
    // user specified operating parameters
    // Databits, Parity, Stopbits - Settings in Line Control Register
    U1LCR = (mode & ~(1 << UART1_LCR_DLAB));    // clear DLAB "on-the-fly"
    // setup FIFO Control Register (fifo-enabled + xx trig) 
    U1FCR = fmode;
} int uart1Putch(int ch)
{
    while (!(U1LSR & ULSR_THRE))        // wait for TX buffer to empty
        continue;               // also either WDOG() or swap()
    U1THR = (uint8_t) ch;       // put char to Transmit Holding Register
    return (uint8_t) ch;        // return char ("stdio-compatible"?)
}
const char *uart1Puts(const char *string)
{
    char ch;
    while ((ch = *string)) {
        if (uart1Putch(ch) < 0)
            break;
        string++;
    }
    return string;
}
int uart1TxEmpty(void)
{
    return (U1LSR & (ULSR_THRE | ULSR_TEMT)) == (ULSR_THRE | ULSR_TEMT);
}
void uart1TxFlush(void)
{
    U1FCR |= UFCR_TX_FIFO_RESET;        // clear the TX fifo
}

/* Returns: character on success, -1 if no character is available */
int uart1Getch(void)
{
    if (U1LSR & ULSR_RDR)       // check if character is available
        return U1RBR;           // return character
    return -1;
}