xmitmessage.asm

来自「ADI 公司的DSP ADSP21369 EZ-KIT LITE开发板的全部源代」· 汇编 代码 · 共 30 行

/* This program transmits a string over the UART0
Inputs - R0 - Address of string to be sent
         R1 - Length of string to be sent
*/

#include <def21369.h>

.global _xmitmsg;
.section/pm seg_pmco;
_xmitmsg:

i4=r0;
/* loop to transmit welcome message in core driven mode */
lcntr = r1, do transmit_welcome until lce;
waiting: ustat1 = dm(UART0LSR);
bit tst ustat1 UARTTHRE;
if not tf jump waiting;

nop;

r0 = dm(i4,1);
transmit_welcome: dm(UART0THR) = r0;

/* poll to ensure UART has completed the transfer */
waiting1: ustat1 = dm(UART0LSR);
bit tst ustat1 UARTTEMT;
if not tf jump waiting1;
_xmitmsg.end:
rts;