Texas Instruments TMS320C3x - Manual (Page 722)

TMS320C31 Boot Loader Source Code
B-5 TMS320C31 Boot Loader Source Code
NOP *AR1++(1) ; jump last half word from mem. word
LDI sub_h,AR3 ; half word size subroutine
; address –> AR3
LSH 1,R1 ; test bit 4 of mem. width word
BN load0 ; if ’1’ start PGM loading
; (16 bits width)
LDI sub_b,AR3 ; byte size subroutine address –> AR3
ADDI 2,AR1 ; jump last 2 bytes from mem. word
load0 CALLU AR3 ; load new word
; according to mem. width
STI R1,*+AR0(64h) ; set primary bus control
load2 CALLU AR3 ; load new word according to
; mem. width
LDI R1,RC ; set block size for repeat loop
CMPI 0,RC ; if 0 block size start PGM
BZ AR2
SUBI 1,RC ; block size –1
CALLU AR3 ; load new word according to
; mem. width
LDI R1,AR4 ; set destination address
LDI R0,R0 ; test start address loaded flag
LDIZ R1,AR2 ; load start address if flag off
LDI –1,R0 ; set start & dest. address flag on
SUBI 1,AR3 ; sub address with loop
CALLUAR3 ; load new word according to
; mem. width
LDI 1,R0 ; set dest. address flag off
ADDI 1,AR3 ; sub address without loop
BR load2 ; jump to load a new block
; when loop completed
.space 1
serial LDI sub_s,AR3 ; serial words subroutine
; address –> AR3
LDI 111h,R1 ; R1 = 0000111h
STI R1,*+AR0(43h) ; set CLKR,DR,FSR as serial port pins
LDI 0A30h,R2
LSH 16,R2 ; R2 = A300000h
STI R2,*+AR0(40h) ; set serial port global
; ctrl. register
BR load2 ; jump to load 1st block
.space 29
loop_s RPTB load_s ; PGM load loop
sub_s TSTB 20h,IF
BZ sub_s ; wait for receive buffer full
AND 0FDFh,IF ; reset interrupt flag