43 lines
1.5 KiB
C
43 lines
1.5 KiB
C
#define GPIO_FUNC_SEL0 0x80000018 /* GPIO 15 - 0; 2 bit blocks */
|
|
|
|
#define BASE_UART1 0x80005000
|
|
#define UART1_CON 0x80005000
|
|
#define UART1_STAT 0x80005004
|
|
#define UART1_DATA 0x80005008
|
|
#define UR1CON 0x8000500c
|
|
#define UT1CON 0x80005010
|
|
#define UART1_CTS 0x80005014
|
|
#define UART1_BR 0x80005018
|
|
|
|
#include "embedded_types.h"
|
|
|
|
__attribute__ ((section ("startup")))
|
|
void main(void) {
|
|
/* Restore UART regs. to default */
|
|
/* in case there is still bootloader state leftover */
|
|
|
|
*(volatile uint32_t *)UART1_CON = 0x0000c800; /* mask interrupts, 16 bit sample --- helps explain the baud rate */
|
|
|
|
/* INC = 767; MOD = 9999 works: 115200 @ 24 MHz 16 bit sample */
|
|
#define INC 767
|
|
#define MOD 9999
|
|
*(volatile uint32_t *)UART1_BR = INC<<16 | MOD;
|
|
|
|
/* see Section 11.5.1.2 Alternate Modes */
|
|
/* you must enable the peripheral first BEFORE setting the function in GPIO_FUNC_SEL */
|
|
/* From the datasheet: "The peripheral function will control operation of the pad IF */
|
|
/* THE PERIPHERAL IS ENABLED. */
|
|
*(volatile uint32_t *)UART1_CON = 0x00000003; /* enable receive and transmit */
|
|
*(volatile uint32_t *)GPIO_FUNC_SEL0 = ( (0x01 << (14*2)) | (0x01 << (15*2)) ); /* set GPIO15-14 to UART (UART1 TX and RX)*/
|
|
|
|
uint8_t c;
|
|
while(1) {
|
|
// *(volatile uint32_t *)UART1_DATA = (uint8_t)'U';
|
|
if(*(volatile uint32_t*)UR1CON > 0) {
|
|
/* Receive buffer isn't empty */
|
|
/* read a byte and write it to the transmit buffer */
|
|
c = *(volatile uint32_t *)UART1_DATA;
|
|
*(volatile uint32_t *)UART1_DATA = c;
|
|
}
|
|
};
|
|
}
|