URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [bootloaders/] [orpmon/] [drivers/] [uart.c] - Rev 745
Go to most recent revision | Compare with Previous | Blame | View Log
#include "support.h" #include "board.h" #include "uart.h" #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) #define WAIT_FOR_XMITR \ do { \ lsr = REG8(UART_BASE + UART_LSR); \ } while ((lsr & BOTH_EMPTY) != BOTH_EMPTY) #define WAIT_FOR_THRE \ do { \ lsr = REG8(UART_BASE + UART_LSR); \ } while ((lsr & UART_LSR_THRE) != UART_LSR_THRE) #define CHECK_FOR_CHAR (REG8(UART_BASE + UART_LSR) & UART_LSR_DR) #define WAIT_FOR_CHAR \ do { \ lsr = REG8(UART_BASE + UART_LSR); \ } while ((lsr & UART_LSR_DR) != UART_LSR_DR) #define UART_TX_BUFF_LEN 32 #define UART_TX_BUFF_MASK (UART_TX_BUFF_LEN -1) char tx_buff[UART_TX_BUFF_LEN]; volatile int tx_level, rx_level; void uart_init(void) { int divisor; float float_divisor; /* Reset receiver and transmiter */ REG8(UART_BASE + UART_FCR) = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_4; /* Disable all interrupts */ REG8(UART_BASE + UART_IER) = 0x00; /* Set 8 bit char, 1 stop bit, no parity */ REG8(UART_BASE + UART_LCR) = UART_LCR_WLEN8 & ~(UART_LCR_STOP | UART_LCR_PARITY); /* Set baud rate */ float_divisor = (float) IN_CLK/(16 * UART_BAUD_RATE); float_divisor += 0.50f; // Ensure round up divisor = (int) float_divisor; REG8(UART_BASE + UART_LCR) |= UART_LCR_DLAB; REG8(UART_BASE + UART_DLL) = divisor & 0x000000ff; REG8(UART_BASE + UART_DLM) = (divisor >> 8) & 0x000000ff; REG8(UART_BASE + UART_LCR) &= ~(UART_LCR_DLAB); } void uart_putc(char c) { unsigned char lsr; WAIT_FOR_THRE; REG8(UART_BASE + UART_TX) = c; if(c == '\n') { WAIT_FOR_THRE; REG8(UART_BASE + UART_TX) = '\r'; } WAIT_FOR_XMITR; } char uart_getc(void) { unsigned char lsr; char c; WAIT_FOR_CHAR; c = REG8(UART_BASE + UART_RX); return c; } char uart_testc(void) { if((REG8(UART_BASE + UART_LSR) & UART_LSR_DR) == UART_LSR_DR) return REG8(UART_BASE + UART_RX); else return 0; }
Go to most recent revision | Compare with Previous | Blame | View Log