Texas Instruments TMS320C3 Series, User Manual, Page: 130 / 166

Communications Kernel Source Code
A-2
;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––;
; TMS320C3x DSK COMMUNICATIONS AND DEBUG MONITOR KERNAL ;
; Texas Instruments Incorporated ;
; (C) 1995,1996 ;
;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––;
.start ”vectors”,0x809FC1
.start ”kernel” ,vectors–0xAB ; Use size report from DSK3A
.start ”sstack” ,0x809F00 ; output to pack to end of RAM
.entry START
;=====================================================================;
; COMMUNICATION MONITOR START ;
; ;
; STACK SPACE ;
; ––––––––––– ;
; A section of unoccupied free memory of STACKSIZE size words just ;
; below the kernel is used on startup for initialization and stack ;
; space. If more (or less) stack space is required, a new stack ;
; pointer value can be initialized within the users applications code ;
; to any location, or by re–assembling this code with a new STACKSIZE ;
; ;
; When initialization is complete, the startup stub can be safely ;
; overwritten since it is no longer needed. In this case the startup ;
; stub is placed after the stack. Another ’safe’ location would be ;
; a section of memory which is used for I/O or uninitialized data. ;
; ;
; This section of code also initializes the timers which are used by ;
; the PAL to create the PWM signal which drives the LED. The rate ;
; at which the LED changes color is F0–F1 where F0 and F0 are the two ;
; timer output frequencies. (See the Users Guide ;
;=====================================================================;
.sect ”sstack”
stack: .word stack–1 ; start of kernel stack
MMRBASE .word 0x00808000 ;
PRD0 .word 0x0000A000 ;
PRD1 .word 0x0000A060 ;
TSTART .word 0x000003C3 ;
START ldp @START ; Set up stack and other params
ldi @stack,SP ;
;=======================
ldi @MMRBASE,AR0 ; Init timers for slow PWM modulation
ldi 3,R0 ; HALT timers
sti R0,*+AR0(0x20) ;
sti R0,*+AR0(0x30) ;
sti R0,*+AR0(0x24) ; Init count registers
sti R0,*+AR0(0x34) ;
ldi @PRD0,R0 ; Init periods
sti R0,*+AR0(0x28) ;
ldi @PRD1,R0 ;
sti R0,*+AR0(0x38) ;
ldi @TSTART,R0 ; Start timers
sti R0,*+AR0(0x20) ;
sti R0,*+AR0(0x30) ;
b spin0 ;