GM-205610-000 DeLorme, GM-205610-000 Datasheet - Page 24

• Manufacturer Part Number: GM-205610-000
• Description: MODULE GPS RCVR GPS2056-10
• Manufacturer: DeLorme

Specifications of GM-205610-000

• Frequency: 1.575GHz
• Data Rate - Maximum: 57.6 kbps
• Modulation Or Protocol: GPS
• Applications: GPS Receiver
• Current - Receiving: 50mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40 Pin
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Sensitivity: -
• Memory Size: -
• Other names: GM-205610-000TR

External Serial Memory
GPS Data Backup in the External Memory
In order to have a short time to fix (TTF) at every system startup, the GPS software can benefit from some vital data (like almanac,
ephemeris, nco frequency offset, etc.) stored in a backup memory and updated up to the last software execution. For these
reasons the consistency on the GPS backup data must be preserved even if the system is turned OFF or it is in a low power mode.
To accomplish this feature, the STA2056 (Palinuro) chip has a small backup SRAM inside, 4k bytes in size and powered by the
backup power supply. This means that the final system needs to also have a battery onboard to supply the backup power rails.
In addition to the internal backed-up SRAM memory, ROM software version 4.30.03+PAL has added the ability to store the GPS
data (and also some other user data) into an external serial (SPI) non volatile memory. The internal backed-up SRAM management
is always available, so the user is free to decide if they want to use additional external memory to the final system layout. Due
to the serial connection the access to the non volatile memory (read/write) is slower than accessing the internal SRAM. To
overcome any problems when the GPS software must access to read and/or store data into backup memory, the software has
been structured to keep the same interface between the GPS software and the internal SRAM backup data and a dedicated task
(low priority task) to update in the “background” external memory, while reading the new values from the internal one. At every
system startup, if the internal SRAM data are lost, the backup data will be restored from the serial memory (it takes less than 2
seconds). In this way the software is exactly the same (with the external memory or without it) and the user needs only to connect
the external memory with the right GPIO configurations.
Adding the external non volatile memory to the final system layout adds an extra feature: the ability to store any other kind of data
together with the GPS data backup (e.g. user application data). The management of memory area is based on a file system that
provides all the features to create new directories and to read/store data; it is also responsible to erase a sector as soon as it
becomes full to keep safe all the last updates in each directory. A set of NMEA commands are available to access, with a host
controller, the external non-volatile memory (refer to the “NMEA Software Commands” section above for further details).
Supported Memories and Schematics
Three different types of memory are supported by the ROM software version 4.30.03+PAL. Below are the hardware connections
and configuration schematics for the supported type of memory. If no external memory is available on board, the two configuration
pins must be unconnected or connected to a pull-up resistor.
1) EEPROM memory (M95128) to address a low cost solution, with 16 K bytes of memory that is available for the GPS data
backup and few additional user data.
2) 1 Mbit FLASH memory (M25P10) to have a long lifetime and to have more memory space to use as additional backup
memory by the user application.
3) 4 Mbit FLASH memory (M25P40) to have much more space for the user needs.
GPS2056
GPS2056
GPS2056
(P0_4) 21
(P0_5) 22
(P0_6) 23
(P0_2) 19
(P0_7) 24
(P0_3) 20
(P0_4) 21
(P0_5) 22
(P0_6) 23
(P0_2) 19
(P0_7) 24
(P0_3) 20
(P0_3) 20
(P0_4) 21
(P0_5) 22
(P0_6) 23
(P0_2) 19
(P0_7) 24
10K
10K
CS
MISO
MOSI
CLK
CS
MISO
MOSI
CLK
10K
10K
CS
MISO
MOSI
CLK
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