MP8830
Pass Through Mode
1.
2.
AENL, BENL & CENL should be held high during pass-through mode. ADCs and DACs will not work properly during pass-through.
Pass-through mode enable. When CREN is high, pass-through mode between the ADC and DAC ports is enabled. RNW controls the direction
of pass-through operation.
3.
READ not WRITE signal. RNW controls the direction of the pass-through operation when CREN is high, and has no impact when CREN is low.
WhenRNWishigh, datapassesfromtheDACporttotheADCport. WhenRNWislow, datapassesfromtheADCporttotheDACport. Notethe
port connections are: CD5; AD0; CD6; AD1;...;CD14; AD9.
CREN
RNW
External circuits must stop
driving CD (5-14) when RNW falls
and CREN is high
External circuits can
start driving CD (5-14)
t
17
t
17
CD
(5-14)
t
13
t
13
t
17
t
14
t
14
t
17
AD
(0-9)
Chip drives AD(0-9)
data from last conversion
Chip stops
External circuit can
Note: external circuits must stop
driving AD(0–9) when CREN falls
driving AD (0-9) start driving AD (0-9)
CREN
RNW
Chip stops driving CD(5-14)
External circuits must stop
driving CD (5-14) when CREN rises
and RNW is low
External circuits can
start driving CD(5-14)
CD
(5-14)
t
17
t
14
t
14
t
17
t
13
t
13
t
17
AD
(0-9)
Chip stops
driving AD (0-9)
External circuits can
start driving AD(0-9)
External circuits must
stop driving AD (0-9)
Chip drives AD(0-9)
data from last conversion
T
Pass through delay from CD(5-14) to AD(0-9)
Pass through delay from AD(0-9) to CD(5-14)
Pass through set up time
13
T
14
T17
Figure 4. Timing for Pass Through Mode Operation
Rev. 1.00
9
EXAR [ EXAR CORPORATION ]
