GE IC697VAL348 TV Converter Box User Manual


 
3-6 IC697VAL348 8-Channel, 16-bit Digital-to-Analog Converter Board User’s Manual GFK-2059
– December 2001
3
Delayed DAC Update Mode
The DELAYED DAC UPDATE MODE operation is described in “Delayed DAC Update Mode”
on page 4-4. This mode must have previously been enabled by the jumper configuration in
“Program Controlled and External Start Convert Mode” on page 2-9. There are two ways for a
DAC channel to be updated after the 16-bit word is loaded into the DAC's first register. The first
way is under program control when data bit D9 is written high to the CSR. It should be noted that
when setting D9 to initiate the DAC update that control bits D8, and D11 through D14 should be
set or reset according to where the user wants the converted output to be routed, (refer to Table 3-4
on page 3-4 and Table 3-5 on page 3-5). Also, a previously loaded DAC may be updated by an
external trigger input from another device. A programming example of the DELAYED DAC
UPDATE MODE is detailed in “Program Example (Delayed DAC Update Mode)” on page 3-9.