From 0ba4e6e322addb8ed678d0b3d6fb81328a6f33be Mon Sep 17 00:00:00 2001
From: ymherklotz <ymherklotz@gmail.com>
Date: Tue, 16 Jan 2018 12:16:38 +0000
Subject: Reorganising and adding lab2

---
 lab1/RTDSP/load.asm | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 lab1/RTDSP/load.asm

(limited to 'lab1/RTDSP/load.asm')

diff --git a/lab1/RTDSP/load.asm b/lab1/RTDSP/load.asm
new file mode 100644
index 0000000..3144acc
--- /dev/null
+++ b/lab1/RTDSP/load.asm
@@ -0,0 +1,65 @@
+; ***************************************************************************************
+;			        DEPARTMENT OF ELECTRICAL AND ELECTRONIC ENGINEERING
+;					               IMPERIAL COLLEGE LONDON 
+;
+; 				       EE 3.19: Real Time Digital Signal Processing
+;					         Course  by: Dr Paul Mitcheson
+;
+;				        LAB 1: Getting Started with the TI C6x DSP 
+;
+; 				            *********** LOAD.ASM ***********
+;
+;	Part of the volume example. Demonstrates that assembly code can be called from C.
+;		          Puts a dummy load on processor which can be varied
+;		                  by modiying the value of processingLoad
+;				(Where ProcessingLoad is a variable passed to the function in C).
+; ***************************************************************************************
+; 				         Modified by D. Harvey: 24 April 2006
+;				Modified to include resource references 23 Jan 2008
+; ***************************************************************************************
+;
+; 
+        .global _load
+
+        .text
+
+N       .set    1000
+
+;
+;  ********************************* _load description **********************************
+;  This function simulates a load on the DSP by executing N * processingLoad
+;  instructions, where processingLoad is the input parameter to load() from volume.c:
+;
+;  								load(processingLoad);
+;
+;  The loop is using 8 instructions. One instruction for sub, nop and b, plus nop 5.
+;  (The extra nop added after sub is to make the number of instructions in the loop 8).
+;  By dividing  N * processingLoad by 8 and using the result as the loop counter,
+;  N * processingLoad = the number of instruction cycles used when the function is called.
+;
+;  See Real Time Digial signal processing by Nasser Kehtarnavaz (page 146) for more 
+;  info on mixing C and Assembly.
+; ****************************************************************************************
+;
+_load:
+
+        mv 		.s2 	a4, b0      ; move parameter (processingLoad) passed from C into b0 
+  [!b0] b 		.s2 	lend  		; end code if processingLoad is zero 
+        mvk 	.s2  	N,b1		; set b1 to value of N (set above as 1000)
+        mpy 	.m2 	b1,b0,b0	; N * processingLoad -> b0
+        nop							; stall the pipeline
+        shru	.s2 	b0,3,b0    	; Divide b0 by 8 (b0 will be used as the loop counter)
+
+		
+loop:					; *************** 8 Instruction Loop ******************
+        sub 	.d2 	b0,1,b0		; b0 - 1 -> b0
+        nop							; added to make loop code 8 instruction cycles long
+   [b0] b 		.s2 	loop		; loop back if b0 is not zero
+        nop 			5			; stall the pipeline
+						; ******************* End of Loop *********************
+
+lend:   b 		.s2 	b3			; branch to b3 (register b3 holds the return address)
+        nop 			5           ; stall the pipeline
+        
+        .end
+
-- 
cgit