Texas Instruments TMS320C3x - Manual (Page 230)

DMA Interrupts
7-46
ISR_n: PUSH ST ;
PUSH DP ; Save registers
PUSH R0 ;
LDI 0, DP ; Clear Data-page Pointer
LDI @DUMMY_INT, R0 ; If DUMMY_INT is 0 or positive,
BNN ISR_n_START ; go to ISR_n_START
STI DP, @DUMMY_INT ; Set DUMMY_INT = 0
POP R0 ;
POP DP ;
POP ST ; Housekeeping, return from interrupt
RETI ;
ISR_n_START: .
. ; Normal interrupt service routine
. ; Code goes here
LDI INT_Fn, R0 ;
AND IF, R0 ; If ones in IF reg match
BNZ ISR_n_END ; INT_Fn, exit ISR
LDI 0, DP ; Otherwise clear
LDI 0FFFFh, R0 ; DP and set
STI R0, @DUMMY_INT ; DUMMY_INT negative & exit
ISR_n_END:
POP R0 ;
POP DP ; Exit ISR
POP ST ;
RETI ;