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参数资料
| 型号： | GP2000 |
| 厂商： | Mitel Networks Corporation |
| 英文描述： | () |
| 中文描述： | （） |
| 文件页数： | 4/25页 |
| 文件大小： | 256K |
| 代理商： | GP2000 |
12
GP2000 – GPS CHIPSET DESIGNER’S GUIDE
SOFTWARE OVERVIEW
The GPS Architect runs a compiled binary image which has
been down-loaded from a PC running the ARM Toolkit shell.
The ARM Toolkit uses the C programming language for source
code for the GPS Architect.
Software Attributes
340 KBytes of ‘C’ source code
82 KBytes of ‘H’ include files
8 KBytes of ‘S’ assembler files
157 KBytes executable (40K332bit)
Compiles with ARM Toolkit v2.0
Concurrent Tasks
The software performs the following concurrent tasks:
Read the correlator channel accumulators in the GP2021
Control the correlator channel tracking loops
Monitor the loop lock conditions
Update the receiver position/velocity estimates
Parse the GPS Data message received from the satellites
Collect measurement blocks
Predict satellite positions with respect to observer, based on
ephemeris data
Control satellite selection strategy
Produce RS232 output data stream
Check for existence of RTCM SC-104 DGPS data for
differential corrections, and parse
Task-Switched Operating System
The GPS Architect software operates under a simple task
switching operating system to provide a concurrent structure of
operations which lends itself to the requirements of GPS signal
processing and software.
The task-switched operating system consists of interrupt and
task driven routines. Only one task can be active at any time.
The main source of interrupt is derived from the GP2021
ACCUM_INT signal (50505
s period default — set to 900025s
in GPS Architect), and is serviced by the Interrupt Service Rou-
tine (ISR). The ISR controls the maintenance of the GPS Archi-
tect operating system and processing of the raw GP2021 accu-
mulation data for maintaining the correlator signal tracking loops.
SOFTWARE STRUCTURE
Task Management
GPS Architect has 7 defined tasks and 1 interrupt service
routine. New tasks can easily be added by the user.
Tasks can be either active or suspended. Only one task is
active at a time. Tasks suspend themselves upon partial or full
completion.
Each concurrent software task takes one of two general
forms:
1. A task which is to be reactivated at fixed time intervals
2. A task which is to be suspended for a fixed time interval
Task priority detemines which task gets the processor dur-
ing task conflict. The Main() task is always set to have the low-
est priority. Processor retention can be achieved by disabling
task-switching or by disabling (masking) GP2021 sourced in-
terrupts.
A task suspension routine operates within the operating sys-
tem, to suspend a task’s operation for a defined number of TlCs
(1 TIC is 00999999s).
Tasks can be added or removed from the software by amend-
ing the global Task Control Block structure, TCB. The ordering
of the tasks in the declaration of TCB is by task priority.
For each task the TCB data entries are:
Pointer to task start address
Pointer to task’s stack (initialise as NULL)
Task stack pointer at start-up (initialise as 0)
Task stack pointer at suspension (initialise as 0)
Task name
Size of task stack
Task Descriptions
The following sections contain descriptions for the GPS
Architect software interrupt routine and tasks. An overview of
the software concurrent task structure is shown in Fig. 13.
Interrupt Routine
Upon an interrupt from the GP2021 the following actions
occur:
Saving of the current task’s context.
Reading of the new accumulation data.
Updating of the code, carrier and data demodulation loops.
Input and output of data for the GP2021 DUART monitor
channel (channel B by default).
Switching of the restore task, if necessary.
Restoration of the restored task’s context.
TTakeMeas()
The TTakeMeas() task’s primary function is to collect meas-
urement data from the active channels to be used in the naviga-
tion solution. Under appropriate conditions it also performs
processing to aid the acquisition and re-acquisition of satellite
signals.
TNav()
The TNav() task determines the navigation solution from the
data supplied in the channels’ measurement blocks. All avail-
able data is used in a least-squares solution. Under appropriate
conditions a constrained 2-D solution is produced when meas-
urements from only 3 satellites are available.
TDisplay()
The TDisplay() task constructs the output data sentences for
the GP2021 DUART monitor channel. The constructed sen-
tences are stored in an output buffer awaiting transmission.
TRTCM()
The TRTCM() task checks and decodes RTCM SC-104
DGPS correction data supplied through the GP2021 DUART
port A. Message types 1, 2 and 9 are recognised and used in
the navigation solution if valid.
TProcSbf()
The TProcSbf() task decodes and validates the received
satellite data message. It also, as appropriate, maintains the
satellite position prediction model for the almanac and ephemeris
data and performs the initial setting of the receiver clock.
TAlloc()
The TAlloc() task is used to check for received User com-
mands from a PC monitor (e.g. WINMON) and to update the
allocation of satellites to channels.
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相关代理商/技术参数 |
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|---|---|
| GP20-005R | 制造商:FRONTIER 制造商全称:Frontier Electronics. 功能描述:2A GENERAL PURPOSE PLASTIC RECTIFIER |
| GP2000-D11-L25-0.3 | 制造商:t-Global Technology 功能描述:THERMAL PAD TUBE 11X25X0.3MM |
| GP2000-D11-L30-0.3 | 制造商:t-Global Technology 功能描述:THERMAL PAD TUBE 11X30X0.3MM |
| GP2000-D13.5-L25-0.3 | 制造商:t-Global Technology 功能描述:THERMAL PAD TUBE 13.5X25X0.3MM |
| GP2000-D13.5-L30-0.3 | 功能描述:THERMAL PAD TUBE 13.5X30X0.3MM 制造商:t-global technology 系列:GP2000 零件状态:有效 使用:- 形状:圆形 外形:30.00mm x 13.50mm 厚度:0.012"（0.305mm） 材料:硅树脂橡胶 粘合剂:- 底布，载体:- 颜色:绿 热阻率:- 导热率:1.3 W/m-K 标准包装:1 |
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