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Open AT ^® Release version:
4.10

Sample - External Storage

Changes
Dependencies
Application Description

Changes

V3.00 : Initial revision
V4.00 : New call stack declaration format; New +CHIP command to select the used external storage chip.
V4.10 : Add a new external storage chip.

Dependencies

This sample depends on the following libraries :

MultiApp
This MultiApp sample library provides start/stop mechanism to handle several running ADL applications.
Drivers
This Drivers sample ADL Library allows applications to use directly some specefic devices, plugged on SPI or I2C bus.

Application Description

This application uses the Drivers library to access external storage chips.

As this application uses the MultiApp library, the following start/stop command has to be used to control the application execution.

AT+EXTSTART (External Storage start/stop command)

Command	Answers
AT+EXTSTART?	+EXTSTART: <state> OK
AT+EXTSTART=?	+EXTSTART: (0-1) OK
AT+EXTSTART= <state>	+CME ERROR: 3 or OK

Parameter	Values range	Description	Default value
state	0-1	The current application running state. This parameter is stored in non-volatile memory.	0

The init entry point sent to the MultiApp library is the es_init() function. The start/stop entry points linked to the +EXTSTART command are the es_start() and es_stop() functions.

The application uses the Drivers library to store and read bytes in/from an external storage chip. It provides two AT commands, for each write and read process, and another one to select the current chip.

AT+CHIP (External storage chip selection command)

Command	Answers
AT+CHIP=?	+CHIP: (0-2) OK
AT+CHIP?	+CHIP: <chip> OK
AT+CHIP= <chip>	OK

Parameter	Values range	Description	Default value
chip	0-2	Used chip ID (stored in a flash object) 0: M95640 SPI E2P chip, connected on SPI2 bus 1: M24C64 I2C E2P chip, connected on I2C bus 2: NAND flash chip, connected on Parallel bus	0

AT+WRITE (External storage chip write command)

Command	Answers
AT+WRITE=?	+WRITE: (0-1FFF or 7FFFFF) , (1-64 or 128) OK
AT+WRITE= <address> , <data>	OK

Parameter	Values range	Description	Default value
address	0-1FFF or 7FFFFF	Data start address of the bytes(or words for the NAND) to store, in hexadecimal format	mandatory
data	1-64 or 128	Bytes (or Word) to write in hexadecimal format 1-64 (or 128) is the maximum of bytes (or Word for the NAND) to write	mandatory

For the NAND flash, the maximum number of consecutive partial page program operations allowed in the same page is three. To avoid this protection, a Block Erase command is issued before any page program by the command +WRITE

AT+READ (External storage chip read command)

Command	Answers
AT+READ=?	+READ: (0-1FFF or 7FFFFF) , (1-127) OK
AT+READ= <address> ,[ <length> ]	+READ: <address>,<data> OK

Parameter	Values range	Description	Default value
address	0-1FFF or 7FFFFF	Data start address of the bytes to read, in hexadecimal format	mandatory
length	1-127	Maximum of bytes (or Word for the NAND) to read	1
data	NA	Read bytes (or Word for the NAND), in hexadecimal format	NA

Updated: Tue Sep 19 17:08:22 CEST 2006;