ST20-GP6 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
Manufacturer
ST20-GP6 Datasheet PDF : 123 Pages
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ST20-GP6
erator. Note, the PRNphase0-11 register should only be updated when the PRNphase0-11WrEn
register has been cleared by the hardware.
PRNphase0-11WrEn DSP base address + #40 to #6C
Bit
Bit field
Function
0
PRNphaseWrEn Set when the corresponding PRNphase0-11 register is set.
Read only
Table 3.5 PRNphase0-11WrEn register format
NCOfrequency0-11 registers
The NCOfrequency0-11 registers hold a signed 18-bit value that is added repetitively, ignoring
overflows, to the accumulated NCO phase from which the NCO sine and cosine waveforms are
generated. The addition is performed at a 264 KHz rate (16.368MHz/62). The accumulated NCO
phase is not accessible to the software, but can be cleared when initialising the channel if enabled
by the DSPControl register.
Each unit value in the NCOfrequency0-11 register represents 264KHz/(218), i.e.
1.007080078125 Hz.
If the extreme values are written, #1FFFF and #20000, the sine wave generated will be at approxi-
mately +132 KHz, and precisely -132 KHz respectively.
NCOfrequency0-11 DSP base address + #80 to #AC
Write only
Bit
Bit field
17:0 NCOfrequency
Function
NCO frequency as a signed 18-bit value.
Table 3.6 NCOfrequency0-11 register format
NCOphase0-11 registers
The NCOphase0-11 registers contents are added to the accumulated phase to correct the carrier
for the final 1 Hz that cannot be resolved by the NCO frequency. This addition is not cumulative,
and the value must be updated regularly by the software as a result of carrier phase errors mea-
sured on the satellite signal. The register holds a signed 7-bit field representing +/-180 degrees
total in steps of 2.8125 degrees (360/128).
NCOphase0-11
DSP base address + #C4 to #EC
Write only
Bit
Bit field
6:0
NCOphase
Function
NCO phase as a signed 7-bit value representing +/-180 degrees total in steps of
2.8125 degrees (360/128).
Table 3.7 NCOphase0-11 register format
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