#define OSC_CLOCK 10000000
#define BAUDRATE 9600
-#define P_DIV 1
+#define P_DIV 4
#define P_CLOCK (OSC_CLOCK/P_DIV)
typedef unsigned char u8;
+typedef unsigned int u32;
-void uart0_init(int br) {
- PINSEL0&=~((0x03<<0)|(0x03<<2)); // clear bits 0-3
- PINSEL0|=((1<<0)|(1<<2)); // pin select: tx, rx
+/* memory mapping */
- UART0_LCR|=(1<<7); // enable access to divisor
- UART0_DLL=(P_CLOCK/(br*16))&0xff; // set divisor
- UART0_DLL=((P_CLOCK/(br*16))&0xff00)>>8;
- UART0_LCR&=~(1<<7); // disable access to divisor
+#define MMAP_BL 0x00
+#define MMAP_RAM 0x02
+#define MMAP_EXT 0x03
- UART0_LCR&=~(0x03<<2); // 1 stop bit, no parity
- UART0_LCR|=0x03; // 8 data bits
+void mmap_init(u8 memtype) {
- UART0_FCR=0x01; // activate fifo
+ MEMMAP=memtype;
}
-void uart_send(u8 byte) {
+void uart0_init(void) {
- /* wait for empty transmit buffer */
- while(!(UART0_LSR&(1<<5)))
- continue;
+ /* pin select -> tx rx */
+ PINSEL0=0x05;
- UART0_THR=byte;
+ /* enable fifo */
+ UART0_FCR=0x07;
+
+ /* set dlab + word length */
+ UART0_LCR=0x83;
+
+ /* set baud rate to 9600 @ 10/4 mhz */
+ UART0_DLL=0x10;
+ UART0_DLM=0x00;
+
+ /* unset dlab */
+ UART0_LCR=0x03;
+}
+
+void uart_send(char *txbuf) {
+
+ int i;
+
+ i=0;
+
+ while(txbuf[i])
+ UART0_THR=txbuf[i++];
+ UART0_THR='\n';
+ UART0_THR='\r';
+
+ while(!(UART0_LSR&(1<<6))) {}
}
int main(void) {
+ char txbuf[]="uart0 working";
+
+ /* memory mapping of interrupt vectors to static ram */
+ mmap_init(MMAP_RAM);
+
/* initialization */
- uart0_init(9600);
+ uart0_init();
while(1) {
- uart_send(0x23);
+ uart_send(txbuf);
}
return 0;