LPCOpen Platform  v1.03
LPCOpen Platform for NXP LPC Microcontrollers
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uart.c
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1 /*
2  * @brief UART interrupt example with ring buffers
3  *
4  * @note
5  * Copyright(C) NXP Semiconductors, 2012
6  * All rights reserved.
7  *
8  * @par
9  * Software that is described herein is for illustrative purposes only
10  * which provides customers with programming information regarding the
11  * LPC products. This software is supplied "AS IS" without any warranties of
12  * any kind, and NXP Semiconductors and its licensor disclaim any and
13  * all warranties, express or implied, including all implied warranties of
14  * merchantability, fitness for a particular purpose and non-infringement of
15  * intellectual property rights. NXP Semiconductors assumes no responsibility
16  * or liability for the use of the software, conveys no license or rights under any
17  * patent, copyright, mask work right, or any other intellectual property rights in
18  * or to any products. NXP Semiconductors reserves the right to make changes
19  * in the software without notification. NXP Semiconductors also makes no
20  * representation or warranty that such application will be suitable for the
21  * specified use without further testing or modification.
22  *
23  * @par
24  * Permission to use, copy, modify, and distribute this software and its
25  * documentation is hereby granted, under NXP Semiconductors' and its
26  * licensor's relevant copyrights in the software, without fee, provided that it
27  * is used in conjunction with NXP Semiconductors microcontrollers. This
28  * copyright, permission, and disclaimer notice must appear in all copies of
29  * this code.
30  */
31 
32 #include "chip.h"
33 #include "board.h"
34 #include "string.h"
35 
65 /*****************************************************************************
66  * Private types/enumerations/variables
67  ****************************************************************************/
68 
69 /* Transmit and receive ring buffers */
70 STATIC RINGBUFF_T txring, rxring;
71 
72 /* Ring buffer size */
73 #define UART_RB_SIZE 64
74 
75 /* Transmit and receive buffers */
76 static uint8_t rxbuff[UART_RB_SIZE], txbuff[UART_RB_SIZE];
77 
78 const char inst1[] = "LPC11xx UART example using ring buffers\r\n";
79 const char inst2[] = "Press a key to echo it back or ESC to quit\r\n";
80 
81 /*****************************************************************************
82  * Public types/enumerations/variables
83  ****************************************************************************/
84 
85 /*****************************************************************************
86  * Private functions
87  ****************************************************************************/
88 
89 /*****************************************************************************
90  * Public functions
91  ****************************************************************************/
92 
97 void UART_IRQHandler(void)
98 {
99  /* Want to handle any errors? Do it here. */
100 
101  /* Use default ring buffer handler. Override this with your own
102  code if you need more capability. */
103  Chip_UART_IRQRBHandler(LPC_USART, &rxring, &txring);
104 }
105 
110 int main(void)
111 {
112  uint8_t key;
113 
114  Board_Init();
115  Board_UART_Init();
116 
117  /* Setup UART for 115.2K8N1 */
118  Chip_UART_Init(LPC_USART);
119  Chip_UART_SetBaud(LPC_USART, 115200);
120  Chip_UART_ConfigData(LPC_USART, (UART_LCR_WLEN8 | UART_LCR_SBS_1BIT));
121  Chip_UART_SetupFIFOS(LPC_USART, (UART_FCR_FIFO_EN | UART_FCR_TRG_LEV2));
122  Chip_UART_TXEnable(LPC_USART);
123 
124  /* Before using the ring buffers, initialize them using the ring
125  buffer init function */
126  RingBuffer_Init(&rxring, rxbuff, 1, UART_RB_SIZE);
127  RingBuffer_Init(&txring, txbuff, 1, UART_RB_SIZE);
128 
129  /* Enable receive data and line status interrupt */
130  Chip_UART_IntEnable(LPC_USART, (UART_IER_RBRINT | UART_IER_RLSINT));
131 
132  /* preemption = 1, sub-priority = 1 */
133  NVIC_SetPriority(UART0_IRQn, 1);
134  NVIC_EnableIRQ(UART0_IRQn);
135 
136  /* Initial message sent using blocking method to prevent ring
137  buffer overflow */
138  Chip_UART_SendBlocking(LPC_USART, inst1, sizeof(inst1) - 1);
139  Chip_UART_SendRB(LPC_USART, &txring, inst2, sizeof(inst2) - 1);
140 
141  /* Poll the receive ring buffer for the ESC (ASCII 27) key */
142  key = 0;
143  while (key != 27) {
144  if (Chip_UART_ReadRB(LPC_USART, &rxring, &key, 1) > 0) {
145  /* Wrap value back around */
146  Chip_UART_SendRB(LPC_USART, &txring, (const uint8_t *) &key, 1);
147  }
148  }
149 
150  /* DeInitialize UART0 peripheral */
151  NVIC_DisableIRQ(UART0_IRQn);
152  Chip_UART_DeInit(LPC_USART);
153 
154  return 1;
155 }
156