LPC23XX_LPC24XX UART实例

/***************************************************************************** * uart.c: UART API file for NXP LPC23xx/24xx Family Microprocessors * * Copyright(C) 2006, NXP Semiconductor * All rights reserved. * * History * 2006.07.12 ver 1.00 Prelimnary version, first Release * ******************************************************************************/ #include "LPC23xx.h" /* LPC23xx/24xx definitions */ #include "type.h" #include "target.h" #include "irq.h" #include "uart.h" volatile DWORD UART0Status; volatile BYTE UART0TxEmpty = 1; volatile BYTE UART0Buffer[BUFSIZE]; volatile DWORD UART0Count = 0; /***************************************************************************** ** Function name: UART0Handler ** ** Descriptions: UART0 interrupt handler ** ** parameters: None ** Returned value: None ** *****************************************************************************/ void UART0Handler (void) __irq { BYTE IIRValue, LSRValue; BYTE Dummy; IENABLE; /* handles nested interrupt */ IIRValue = U0IIR; IIRValue >>= 1; /* skip pending bit in IIR */ IIRValue &= 0x07; /* check bit 1~3, interrupt identification */ if ( IIRValue == IIR_RLS ) /* Receive Line Status */ { LSRValue = U0LSR; /* Receive Line Status */ if ( LSRValue & (LSR_OE|LSR_PE|LSR_FE|LSR_RXFE|LSR_BI) ) { /* There are errors or break interrupt */ /* Read LSR will clear the interrupt */ UART0Status = LSRValue; Dummy = U0RBR; /* Dummy read on RX to clear interrupt, then bail out */ IDISABLE; VICVectAddr = 0; /* Acknowledge Interrupt */ return; } if ( LSRValue & LSR_RDR ) /* Receive Data Ready */ { /* If no error on RLS, normal ready, save into the data buffer. */ /* Note: read RBR will clear the interrupt */ UART0Buffer[UART0Count] = U0RBR; UART0Count++; if ( UART0Count == BUFSIZE ) { UART0Count = 0; /* buffer overflow */ } } } else if ( IIRValue == IIR_RDA ) /* Receive Data Available */ { /* Receive Data Available */ UART0Buffer[UART0Count] = U0RBR; UART0Count++; if ( UART0Count == BUFSIZE ) { UART0Count = 0; /* buffer overflow */ } } else if ( IIRValue == IIR_CTI ) /* Character timeout indicator */ { /* Character Time-out indicator */ UART0Status |= 0x100; /* Bit 9 as the CTI error */ } else if ( IIRValue == IIR_THRE ) /* THRE, transmit holding register empty */ { /* THRE interrupt */ LSRValue = U0LSR; /* Check status in the LSR to see if valid data in U0THR or not */ if ( LSRValue & LSR_THRE ) { UART0TxEmpty = 1; } else { UART0TxEmpty = 0; } } IDISABLE; VICVectAddr = 0; /* Acknowledge Interrupt */ } /***************************************************************************** ** Function name: UARTInit ** ** Descriptions: Initialize UART0 port, setup pin select, ** clock, parity, stop bits, FIFO, etc. ** ** parameters: UART baudrate ** Returned value: true or false, return false only if the ** interrupt handler can't be installed to the ** VIC table ** *****************************************************************************/ DWORD UARTInit( DWORD baudrate ) { DWORD Fdiv; PINSEL0 = 0x00000050; /* RxD0 and TxD0 */ U0LCR = 0x83; /* 8 bits, no Parity, 1 Stop bit */ Fdiv = ( Fpclk / 16 ) / baudrate ; /*baud rate */ U0DLM = Fdiv / 256; U0DLL = Fdiv % 256; U0LCR = 0x03; /* DLAB = 0 */ U0FCR = 0x07; /* Enable and reset TX and RX FIFO. */ if ( install_irq( UART0_INT, (void *)UART0Handler, HIGHEST_PRIORITY ) == FALSE ) { return (FALSE); } U0IER = IER_RBR | IER_THRE | IER_RLS; /* Enable UART0 interrupt */ return (TRUE); } /***************************************************************************** ** Function name: UARTSend ** ** Descriptions: Send a block of data to the UART 0 port based ** on the data length ** ** parameters: buffer pointer, and data length ** Returned value: None ** *****************************************************************************/ void UARTSend(BYTE *BufferPtr, DWORD Length ) { while ( Length != 0 ) { /* THRE status, contain valid data */ while ( !(UART0TxEmpty & 0x01) ); U0THR = *BufferPtr; UART0TxEmpty = 0; /* not empty in the THR until it shifts out */ BufferPtr++; Length--; } return; } /****************************************************************************** ** End Of File ******************************************************************************/