Application processor chip integrated with satellite navigation baseband IP and integration method
Technical Field
The invention relates to an integrated satellite navigation baseband IP in an application processor chip, in particular to an application processor chip integrated with the satellite navigation baseband IP and an integration method.
Background
Methods for adding a satellite navigation function to a system requiring satellite navigation equipment, such as a mobile phone, a PDA, or a vehicle navigation system, are classified into three types: firstly, selecting a satellite navigation module; secondly, a navigation chip set (a baseband chip and a radio frequency receiving chip) or a single chip is selected, the two modes have the advantages of simplicity and easiness in use, and the defects of large volume, high cost and large power consumption of the satellite navigation module and the navigation chip set; and thirdly, directly integrating the satellite navigation baseband IP into an application processor chip thereof, processing and producing by adopting the process of the processor chip, and integrating the radio frequency chip into the radio frequency module. The method has the advantages of small volume, low cost and low power consumption, and has the disadvantages of high integration design difficulty and high early-stage cost.
FIG. 1 is a diagram of a conventional satellite navigation system architecture. The method comprises the following steps: CPU, BBRAM navigation historical information memory cell, navigation signal memory cell, N passageway units, asynchronous serial port unit and clock unit of receiving and dispatching.
A navigation signal storage unit: the received information containing all navigation satellite signals is stored.
BBRAM navigation history information storage unit: and storing the main navigation information when the last navigation is finished for starting the next navigation function to realize quick positioning.
A CPU: and the central processing unit controls the operation of the system, and has the functions of protocol processing, positioning calculation, communication and the like.
Channel 1 to channel N: the channel units for capturing, tracking, bit synchronization and frame synchronization have the same function and comprise two functional units of storage and operation. The storage is used for storing all data of the channel operation process and is also called a channel operation storage unit. The operation is a navigation channel operation unit including various operations.
The satellite navigation baseband signal processing adopts an SOC system architecture and is divided into two parts, namely hardware and software.
The software part mainly comprises a baseband circuit capturing strategy control algorithm and a loop tracking control algorithm, interrupt processing, selection of satellite constellation and frequency points, resolving of positioning position and timing information, NEMA-0183 protocol processing of positioning timing information output, A-GNSS protocol processing, communication control of an asynchronous transceiver transmitter and the like, and is processed by a central processing unit CPU (central processing unit), wherein a series of processors of ARM company or CPUs of other companies are usually selected.
The hardware part receives signals output by a radio frequency front end receiving chip, the radio frequency front end chip comprises an ADC unit module, and the output signals are digital signals. The digital signal contains information of all navigation satellites, and each satellite signal is processed by one channel or a plurality of channels. Each channel comprises a storage unit module and an operation unit module, each channel specifically processes satellite signals by capturing, tracking, bit synchronization, frame synchronization, data demodulation, measurement data extraction and the like, and the processing methods of the channels are completely consistent.
At present, a satellite navigation baseband IP is integrated in an application processor chip, and the integration can be performed in multiple layers. Firstly, the satellite navigation baseband IP is completely integrated into an application processor chip; and the other part directly integrates the rest parts into the application processor chip by partially utilizing the resources of the application processor chip, such as a CPU, a serial port and the like. However, the two integration methods do not fully utilize the resources in the application processor chip, so that the satellite navigation baseband IP and the application processor chip are fused deeply.
Disclosure of Invention
The invention aims to solve the technical problems that the existing method for integrating the satellite navigation baseband IP in the application processor chip does not fully utilize resources in the application processor chip and can not enable the satellite navigation baseband IP to be deeply fused with the processor chip, and provides the application processor chip integrating the satellite navigation baseband IP and the integration method.
The technical idea of the invention is as follows: the application processor chip in the equipment such as mobile phone, PDA or vehicle navigation contains one or more CPU, RAM, asynchronous receiving and transmitting serial port unit, history information memory in the processor, clock unit and other resources, when the application processor chip integrates the satellite navigation baseband IP, only a navigation channel arithmetic unit is integrated in the existing application processor chip, and the satellite navigation baseband chip system can be formed by time division multiplexing of the navigation channel arithmetic unit and borrowing the resources of the application processor chip.
The technical scheme of the invention is as follows:
the invention provides an application processor chip integrated with a satellite navigation baseband IP, which comprises a CPU, a historical information storage unit, a navigation signal storage unit, a channel operation storage unit, a clock unit and an asynchronous receiving and transmitting serial port unit;
the navigation channel calculation unit is also included, and the number of the navigation channel calculation units is 1;
the channel operation storage unit is an RAM inside an application processor chip, the RAM is divided into N sections of address spaces by the channel operation storage unit, the RAM of each section of address space corresponds to one channel operation storage unit, N is the maximum channel number configurable inside the application processor chip, N is not less than 4 and is an integer, and the N is programmed and set according to internal resources of the application processor chip;
the N sections of RAM address spaces form a channel operation storage unit of N processing channels of the application processor chip; the navigation channel operation unit adopts time division multiplexing, each channel is allocated with a period of time for operation, and operation results are respectively stored in a channel operation storage unit formed by N processing channels of the application processor chip;
the clock frequency of the clock unit is at least increased to N times of the intermediate frequency sampling frequency of the GPS or the Beidou according to the received GPS signal or the Beidou signal, the GPS is a global satellite positioning system, the intermediate frequency sampling frequency is more than or equal to 4.092MHz, the Beidou is a global satellite navigation system, and the intermediate frequency sampling frequency is more than or equal to 8.184 MHz.
Furthermore, the channel operation storage unit divides the RAM into N sections of address spaces, wherein the value range of N is 8-192, and N is an integer.
Further, the application processor chip is an application processor chip of a mobile phone, a PDA, or a vehicle navigation device.
The invention also provides an integration method of the application processor chip of the integrated satellite navigation baseband IP, which comprises the following steps:
(1) only one navigation channel operation unit of a satellite navigation baseband IP is integrated on the existing application processor chip; the navigation signal storage unit, the channel operation storage unit, the CPU, the historical information storage unit, the clock unit and the asynchronous receiving and transmitting serial port unit utilize internal resources of an application processor chip;
(2) the channel operation storage unit uses an RAM inside an existing application processor chip, the RAM of the channel operation storage unit is divided into N sections of address spaces, the RAM of each section of address space corresponds to one channel operation storage unit, N is the maximum channel number configurable inside the application processor chip, N is not less than 4 and is an integer, and N is programmed and set according to internal resources of the application processor chip;
(3) the clock frequency of the clock unit is at least increased to N times of the intermediate frequency sampling frequency of the GPS or the Beidou according to the received GPS signal or the Beidou signal, the GPS is a global satellite positioning system, the intermediate frequency sampling frequency is more than or equal to 4.092MHz, the Beidou is a global satellite navigation system, and the intermediate frequency sampling frequency is more than or equal to 8.184 MHz. .
In the implementation operation, the three aspects of the integration method of the application processor chip integrated with the satellite navigation baseband IP have no fixed sequence, and a designer can arrange the integration sequence by himself.
Compared with the prior art, the invention has the advantages that:
1. compared with the existing application processor chip integrated with the satellite navigation baseband IP, the invention omits a CPU, a BBRAM navigation history information storage unit, a navigation signal storage unit, a channel operation storage unit in N channel units, an asynchronous receiving and sending serial port unit and a clock unit in the system, and can form the satellite navigation baseband chip system only by integrating one navigation channel operation unit in the existing application processor chip and by time division multiplexing of the navigation channel operation unit and simultaneously borrowing corresponding resources of the application processor chip. The design method makes full use of the resources of the application processor chip and reduces power consumption.
2. The invention is the deep fusion of the satellite navigation baseband IP and the application processor chip, and the memory unit in the channel unit of the satellite navigation baseband IP utilizes the RAM in the application processor chip, thereby being beneficial to the design of a time division multiplexing circuit and the integration of the satellite navigation baseband IP on the application processor chip, and further reducing the area and the power consumption of the circuit.
Drawings
FIG. 1 is a schematic diagram of a conventional satellite navigation system architecture (clock unit not shown);
fig. 2 is a schematic diagram of an architecture of an application processor chip integrated with a satellite navigation baseband IP according to the present invention (a clock unit is not shown).
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 2, the present embodiment provides an application processor chip integrated with a satellite navigation baseband IP, which includes a CPU, a history information storage unit, a navigation signal storage unit, a channel operation storage unit, and an asynchronous serial port transceiver unit;
a navigation signal storage unit: the received information containing all navigation satellite signals is stored into a common RAM memory.
Navigation history information storage unit: and storing historical information needing to be memorized, including main navigation information when the last navigation is finished.
A CPU: and the central processing unit or the multi-core processor is used for controlling the operation of the whole navigation system, and comprises functions of navigation protocol processing, positioning calculation, communication and the like.
Channel 1 operation storage, channel 2 operation storage-channel N operation storage: the storage unit is used for storing all data of the channel operation process and is also called a channel operation storage unit.
Software of the satellite navigation baseband IP runs on a CPU of an application processor chip; historical information of the satellite navigation baseband IP is stored in a historical information memory of the application processor chip; the positioning and timing results are output through an asynchronous receiving and transmitting serial port unit of the application processor chip.
The application processor chip of the integrated satellite navigation baseband IP also comprises 1 navigation channel operation unit which respectively performs operation processing on each channel through time division multiplexing;
the channel operation storage unit is an RAM programmed and set according to internal resources of a processor chip, and divides N sections of RAM address spaces to store processing results of N channels; n is the maximum channel number which can be configured inside the application processor chip, N is not less than 4 and is an integer, and the preferable range of N is 8-192.
The application processor chip of the integrated satellite navigation baseband IP processes satellite signals by using N channel units in the original satellite navigation baseband IP, and changes the navigation channel operation units of the channel units into N times of calling through a time division multiplexing technology, and allocates a period of time to each operation storage channel for operation processing and data storage.
The clock frequency of the clock unit is at least increased to N times of the GPS or the Beidou intermediate frequency sampling frequency according to the received GPS intermediate frequency sampling frequency or the Beidou intermediate frequency sampling frequency, the GPS is a global satellite positioning system, the intermediate frequency sampling frequency is not less than 4.092MHz, the Beidou is a global satellite navigation system, and the intermediate frequency sampling frequency is not less than 8.184 MHz.
When the application processor chip of the integrated satellite navigation baseband IP is designed, only a navigation channel operation unit of the satellite navigation baseband IP needs to be integrated on the application processor chip, and internal resources of the application processor chip are utilized by a CPU (central processing unit), a navigation signal storage unit, a channel operation storage unit, a historical information storage unit, a clock unit and an asynchronous receiving and transmitting serial port unit of the satellite navigation baseband IP;
changing all D triggers in a storage unit in a channel unit of a satellite navigation baseband IP into an RAM in an application processor chip, dividing the RAM in the application processor chip into N sections of address spaces, and giving each channel storage unit the RAM with a specified section of address space for information storage in the channel operation process, wherein N is the maximum channel number configurable in the application processor chip. N is programmed and set according to internal resources of the application processor chip, N is not less than 4 and is an integer, the precision and the accuracy of navigation and the configuration of the application processor chip are comprehensively considered, and the preferable range of N is as follows: 8 to 192;
the clock frequency of the clock unit is improved to be at least N times of the GPS or the Beidou intermediate frequency sampling frequency through the transformation of the clock unit according to the received GPS intermediate frequency sampling frequency or the Beidou intermediate frequency sampling frequency, the GPS is a global satellite positioning system, the intermediate frequency sampling frequency is not less than 4.092MHz, the Beidou is a global satellite navigation system, and the intermediate frequency sampling frequency is not less than 8.184 MHz.
The English abbreviations appearing in the present invention are explained as follows:
adc (analog digital converter): an analog signal/digital signal converter;
bbram (baseband ram): a baseband random access memory;
ram (random Access memory): a random access memory;
IP (intellectual Property): intellectual property rights;
CPU (central processing unit): a central processing unit;
pda (personal Digital assistant): a palm computer;
soc (system on chip): a system-on-chip;
gps (global Positioning system): a global navigation positioning system.