sd.asm

基于凌汛科技 CPU的sd卡驱动源代码。

//*************Default Clock Frequency 3.072MHz*************//
//**************circulation times=1536000*CT/n**************//
//**********CT=circulation time; n=number of "nop"**********//

// Watchdog Reset
.DEFINE P_Watchdog_Clear 0x7012;

.code
.PUBLIC _Delay5us;
_Delay5us:.PROC//Always use r3 for delay counting//
	push r3 to [sp];
	
	r3=2;//4
	
	D5usCirculation:
		nop;
		nop;
		r1=0000000000000001b;//Feed the dog
		[P_Watchdog_Clear]=r1;
		r3-=1;
		jnz D5usCirculation;
	
	pop r3 from [sp];
	
	retf;
.ENDP