Chameleon-PIC Nurve Networks, Chameleon-PIC Datasheet - Page 232

• Manufacturer Part Number: Chameleon-PIC
• Description: MCU, MPU & DSP Development Tools PIC24 & PROPELLER DEV SYSTEM (SBC)
• Manufacturer: Nurve Networks

Specifications of Chameleon-PIC

• Processor To Be Evaluated: PIC24
• Data Bus Width: 16 bit
• Interface Type: USB, VGA, PS/2, I2C, ISP, SPI
• Operating Supply Voltage: 3.3 V, 5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

© 2009 NURVE NETWORKS LLC “Exploring the Chameleon PIC 16-Bit”
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=671884&CatId=564
31.1.3 FLASH Memory Demo (with XModem Protocol Bonus Example)
This demo illustrates how to use the onboard 1MB SPI FLASH memory (Atmel part #T26DF081A). This is not to be
confused with the Propeller chip’s 64K EEPROM. The EEPROM is for the Propeller’s boot image and only directly
accessible by the Propeller chip. The 1 MB FLASH is accessible by the PIC chip via the SPI mux interface. With that in
mind, you might want review the Chameleon API as well as the data sheet for the FLASH memory located on the DVD
here:
DVD-ROM:\ CHAM_PIC \ DOCS \ DATASHEETS \ Atmel_AT26DF081A_FLASH_doc3600.pdf
To use the FLASH API is relatively easy, you open the FLASH memory up, then read or write, then close it. Basically, four
API calls to do everything. However, that’s pretty boring, so we decided to do something a little more interesting. We were
concerned that many newbies would have a hard time putting the FLASH to use since there isn’t a direct way to access it
from the PC. For example, if you could read and write files to it over the USB port that would be ideal. Moreover, if the
Chameleon could act like a FLASH FAT drive that would be great. But, no one has written software to do that, and that’s a
good 1-2 weeks work, so if you’re up to it please do – However, as a conciliation prize, we developed a little “X-Modem”
protocol driver that allows you to download files (of any type) from the PC to the Chameleon into a RAM buffer. Then you
can do what you want with the RAM buffer like write it to the FLASH memory! Figure 31.3 shows a flow diagram of what’s
going on.
Figure 31.3 – The various elements in an X-Modem file transfer.
232