2009-11-18 16:35:44     UART configuration - bf547 RadioTuna custom board

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2009-11-18 16:35:44     UART configuration - bf547 RadioTuna custom board

Rutger Hofman (NETHERLANDS)

Message: 82506   


Prototypes of our newest generation hardware have arrived. Our project started out as a RFID privacy protection tool, but it has widened out into a completely generic RFID handheld tool, see www.rfidguardian.org; this version is christened RadioTuna. We have a motherboard with a beefy Altera FPGA, pluggable analog RFID frontends (various frequencies, no hardware yet), Ethernet, USB, I2S, touchscreen; there is also an expansion connector for all BlackFin pins, which even allows RadioTuna to be used as a generic BlackFin development kit. The BF547, 128MB RAM, RTC and NAND flash are on a separate baby board.


Software-wise: we use u-boot to boot from NAND flash (no NOR flash), and eCos as the application (bare-metal, as far as this community is concerned). u-boot, based on bf548-ezkit, now has working CPU, RAM, UART, NAND, Ethernet (the only thing that caused me troubles). All software and hardware will be open-source (GPL, GPL/eCos, creative commons).


Finally my question: when I started booting u-boot out of NAND flash, UART1 had its RTS/CTS lines disabled, in the GPIO multiplexer as well as in the UART1_MCR config register. I changed these settings by hand in my board file (u-boot/board/bf547-radiotuna/bf547-radiotuna.c); but I cannot find where bf548-ezkit configures its UART1 RTS/CTS, so I wonder if this is the right place.




Rutger Hofman

VU Amsterdam




2009-11-18 18:30:14     Re: UART configuration - bf547 RadioTuna custom board

Mike Frysinger (UNITED STATES)

Message: 82507   


the bf548-ezkit doesnt use RTS/CTS for any of its UARTs.  there is a tracker item open to look into supporting hardware flow control via the normal CONFIG_HWFLOW, but no one has requested/complained, so it has kind of sat there.


plus, none of the bf548-ezkit's out there have RTS/CTS wired correctly in the current PCB, so you cant correctly enable flow control in the first place.


i dont imagine it would take long to implement this stuff if you wanted to discuss  your needs further.