sta8088ex STMicroelectronics, sta8088ex Datasheet - Page 17

• Manufacturer Part Number: sta8088ex
• Description: High Flexible Gps/galileo/glonass/qzss Receiver With Powerful Processing Arm9
• Manufacturer: STMicroelectronics

STA8088EX
3
3.1
3.2
3.3
General description
RF front-end
The RF front-end is able to down-convert both the GPS-GALILEO signal from 1575.42 MHz
to 4.092 MHz (4 Fo, being F0 = 1.023 MHz) and GLONASS signal from 1601.718 MHz to
8.57 MHz.
It embeds high performance LNA minimizing external component count and two LDOs to
supply the internal core facilitating requirements for external power supply. A three bits ADC
converts the IF signals to sign (SIGN) and magnitude (MAG0 and MAG1). They can be
sampled or not by SPI. The magnitude bits are internally integrated in order to control the
variable gain amplifiers. The VGA gain can be also set by the SPI interface.
The RF tuner accepts a wide range of reference clocks (10 to 52 MHz) and can generate
16 Fo, 32 Fo, 48 Fo and 64 Fo sampling clock (GALGPS_CLK and GNS_CLK) for the
baseband.
GPS/Galileo/Glonass/QZSS Base Band (G3BB) processor
STA8088EX integrates G3BB proprietary IP, which is the ST last generation high-sensitivity
baseband processor fully compliant with GPS, Galileo, Glonass and QZSS satellite
systems. Please refer to GPS solution specification and release notes for more details.
The base band receives, from the embedded RF front-end, two separate IF signals codified
in sign-magnitude digital format on 3 bits and the related clocks. The Galileo/GPS
(GALGPS) and Glonass (GNS) signals at the base band inputs are centered on 4.092 MHz
and 8.57 MHz respectively.
The baseband processes the two IF signals performing data codification, sample rate
convertion and final frequency convertion to zero IF before acquisition and tracking
correlations.
The base band processor has the capability of acquire and track the Galileo, GPS and
Glonass signals in a simultaneous or single way, or a combination of the three. The number
of tracking channels to be used is programmable; the not uset tracking channels can be
powered down.
A complete multi-OS software library is provided by ST to handle GPS processing,
managing satellite acquisition, tracking, pseudo-range calculation and positioning,
generating the output in the standard NMEA message format. The library includes support
of ST Self-Trained Assisted GPS (ST-AGPS), a complete and scalable solution for assisting
GPS start-up with autonomous and server-based ephemeris prediction and extension.
MCU subsystem
The implemented subsystem includes an AHB lite bus matrix.
An ARM946 core is embedded in the subsystem and masters the AHB bus. The totally
available TCM SRAM is 256 KB. The amount of memory on ITCM and DTCM can be
configured by the ARM946 (see
DTCM can be configured as 64 + Nd x 16 KB, where Ni + Nd = 8, Ni ≥1.
Doc ID 18357 Rev 1
Table
11). ITCM can be configured as 64 + Ni x 16 KB;
General description
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