Datasheet

LTC1196/LTC1198
26
119698fb
TYPICAL APPLICATIONS
Once RINT is generated the code begins execution at
the label RINT. This code stores the D
OUT
word from the
LTC1198 in the ACC and then stores it in location 200
hex. The data appears in location 200 hex right-justifi ed
as shown in Figure 19. The code is set up to continually
loop, so at this point the code jumps to label TXRX and
repeats from here.
L1196/98 F19
MSB
LSB
X X X X X X X X 7 6 5 4 3 2 1 0
D
OUT
FROM LTC1198 STORED IN TMS320C25 RAM
> 200
Figure 19. Memory Map for the Circuit in Figure 15
LABEL MNEMONIC COMMENTS
AORG
B
0
INIT
ON RESET CODE EXECUTION STARTS AT 0
BRANCH TO INITIALIZATION ROUTINE
AORG
B
>26
RINT
ADDRESS TO RINT INTERRUPT VECTOR
BRANCH TO RINT SERVICE ROUTINE
INIT
AORG
DINT
LDPK
LARP
LRLK
LACK
SACL
STXM
FORT
>32
>0
>1
AR1, >200
>10
>4
0
MAIN PROGRAM STARTS HERE
DISABLE INTERRUPTS
SET DATA MEMORY PAGE POINTER TO 0
SET AUXILIARY REGISTER POINTER TO 1
SET AUXILIARY REGISTER 1 TO >200
LOAD IMR CONFIG WORD INTO ACC
STORE IMR CONFIG WORD INTO IMR
CONFIGURE FSX AS AN OUTPUT
SET SERIAL PORT TO 16-BIT MODE
TXRX LACK
SFSM
RPTK
SFL
SACL
EINT
>44
7
>1
LOAD LTC1198 D
IN
WORD INTO ACC
FSX PULSES GENERATED ON XSR LOAD
REPEAT NEXT INSTRUCTION 8 TIMES
SHIFTS D
IN
WORD TO RIGHT POSITION
PUT D
IN
WORD IN TRANSMIT REGISTER
ENABLE INTERRUPT (DISABLE ON RINT)
RPTK
NOP
2 MINIMIZE THE CONVERSION CYCLE TIME
TO BE 20 CLOCK CYCLES
RINT ZALS
SACL
B
END
>0
*, 0
TXRX
STORE LTC1198 D
OUT
WORD IN ACC
STORE ACC IN LOCATION >200
BRANCH TO TRANSMIT RECEIVE ROUTINE
Figure 20. TMS320C25 Code for the Circuit in Figure 15