GP1020 Datasheet, PDF (30/44 Pages) Zarlink Semiconductor Inc – SIX-CHANNEL PARALLEL CORRELATOR CIRCUIT FOR GPS OR GLONASS RECEIVERS

GP1020
Register bit mapping
Bit
Name
Description
8 CH1_DUMP/OSC When LOW the GP1020
_CHECK
MARK output pin will
output a square wave with a
period of 4·55 microseconds.
(40MHz/182). Because this
clock is derived from the
TCXO, its stability and
accuracy is representative of
the TCXO stability and
accuracy. When HIGH, the
GP1020 MARK output pin will
output a square-wave chang-
ing its level at each DUMP
event in channel 1. These
features are used for test
purposes during ATP of the
GPS sensor unit and the
TEST_OP/MARK bit (bit 4)
must be set to HIGH to get
either of these two test
outputs.CH1_DUMP/
OSC_CHECK is set LOW by
reset.
12 to 9
Interrupt time base selection
with the encoding given in the
following table.
Bit 12
11
10
9
0
0
X
X
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
Bits 12 to 9 are set LOW by reset.
Selected interrupt
timebase period (µs)
505.050
420.875
505.050
589.225
673.400
757.575
841.750
925.925
1010.100
1094.275
1178.450
1262.625
1346.800
High time
(µs)
252.525
84.175
252.525
336.700
336.700
420.875
420.875
505.050
84.175
168.350
84.175
168.350
420.875
Low time
(µs)
252.525
336.700
252.525
252.525
336.700
336.700
420.875
420.875
925.925
925.925
1094.275
1094.275
925.925
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