TLV5614

2.7-V TO 5.5-V 12-BIT 3-

µS QUADRUPLE DIGITAL-TO-ANALOG CONVERTERS

WITH POWER DOWN

SLAS188 – SEPTEMBER 1998

17

POST OFFICE BOX 655303

APPLICATION INFORMATION

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Main Program

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.ps

1000h

.entry

start

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; disable interrupts

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

setc

INTM

; disable maskable interrupts

splk

#0ffffh, IFR; clear all interrupts

splk

#0004h, IMR; timer interrupts unmasked

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; set up the timer

; timer period set by values in PRD and TDDR

; period = (CLKOUT1 period) x (1+PRD) x (1+TDDR)

; examples for TMS320C203 with 40MHz main clock

; Timer rate

TDDR

PRD

;

80 kHz

9

24 (18h)

;

50 kHz

9

39 (27h)

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

prd_val.equ

0018h

tcr_val.equ

0029h

splk

#0000h, temp; clear timer

out

temp, TIM

splk

#prd_val, temp; set PRD

out

temp, PRD

splk

#tcr_val, temp; set TDDR, and TRB=1 for auto–reload

out

temp, TCR

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Configure IO0/1 as outputs to be :

; IO0

CS

– and set high

; IO1

LDAC

– and set high

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

in

temp, ASPCR; configure as output

lacl

temp

or

#0003h

sacl

temp

out

temp, ASPCR

in

temp, IOSR; set them high

lacl

temp

or

#0003h

sacl

temp

out

temp, IOSR

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; set up serial port for

; SSPCR.TXM=1

Transmit mode – generate FSX

; SSPCR.MCM=1

Clock mode – internal clock source

; SSPCR.FSM=1

Burst mode

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

splk

#0000Eh, temp

out

temp, SSPCR; reset transmitter

splk

#0002Eh, temp

out

temp,SSPCR

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; reset the rolling pointer

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

lacl

#000h

sacl

r_ptr

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; enable interrupts

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

clrc

INTM

; enable maskable interrupts

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; loop forever!

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