For SPI use SHIFTOUT. Something like this should work;
Code:
A VAR WORD
B VAR WORD
 
CS VAR PORTB.0  ' chip select
SCK VAR PORTB.1 ' clock
SDI VAR PORTB.2 ' data
LDAC VAR PORTB.3 ' load DAC
 
HIGH CS   
LOW SCK
HIGH LDAC
 
A = %0001111111111100 ' channel A, 2x, active, max output
B = %1001111111111100 ' channel B, 2x, active, max output
 
Main:
  LOW CS ' enable writes
  SHIFTOUT SDI,SCK,0,[A\16]
  HIGH CS 
  PAUSE 5
 
  LOW CS
  SHIFTOUT SDI,SCK,0,[B\16]
  HIGH CS
 
  LOW LDAC ' load both DAC outputs
  PAUSE 5
  HIGH LDAC
 
  PAUSE 5000
  GOTO Main
  END