world leader in high performance signal processing
Trace:

Differences

This shows you the differences between two versions of the page.

hw:cards:cf-ide-nand [2009/06/22 19:10]
127.0.0.1 external edit
hw:cards:cf-ide-nand [2010/09/09 22:02] (current)
Line 36: Line 36:
  
 The card uses Bi-directional BUS switches (IDT QS316245) to perform Bus isolation and 5V to 3.3V logic level translation. In most of the applications a CPLD (Xilinx XC9572XL-7VQ64) as present in the reference design is not necessary. Please refer to the CPLD schematics. The CPLD is mainly used to perform address decoding, and to insert three additional bus setup cycles, to met the lower IDE ATA PIO Mode and CF I/O Mode specifications, to achieve SCLK running up to 80 MHz. The card uses Bi-directional BUS switches (IDT QS316245) to perform Bus isolation and 5V to 3.3V logic level translation. In most of the applications a CPLD (Xilinx XC9572XL-7VQ64) as present in the reference design is not necessary. Please refer to the CPLD schematics. The CPLD is mainly used to perform address decoding, and to insert three additional bus setup cycles, to met the lower IDE ATA PIO Mode and CF I/O Mode specifications, to achieve SCLK running up to 80 MHz.
 +
 +
 +===== Known Issues =====
 + 
 +Recent Linux libata assumes the IDE Interrupt INTRQ staying inactive low the time between the IRQ is requested and the device is configured. 
 +The problem here is that the INTRQ signal output line has high impedance when no devices are selected or interruption is disabled.
 +
 +The CF-IDE-NAND Card however has 10kOhm Pull-Up on INTRQ - which will then cause a 
 +"**irq XX: nobody cared**" error during libata driver initialization.
 +
 +Workaround is to add a stronger (1kOhm) Pull-Down to INTRQ.\\
 +See picture below:\\ 
 +
 + {{:hw:cards:ide_intrq_pull_down.jpg?640|}}
 +
 +On the CF Card socket there is also a pull-up – but there we had no choice since in PC-Card IO mode the Interrupt is asserted Low. So this was a tradeoff, and at the time doing the card – it worked without errors, in all modes.
 +
 +Assuming you are going to use the CF Card Interface in TRUE IDE MODE with interrupt, you need to add this workaround there too. As an alternative use either TRUE IDE MODE without interrupt, the PCMCIA driver with IDE Card Service Drivers or better the CF Common Memory Mode Interface without IDE Interrupt.
 +
  
 ===== Hardware Setup ===== ===== Hardware Setup =====
Line 338: Line 357:
 ====== NAND Flash Introduction ====== ====== NAND Flash Introduction ======
  
-<note> +For information about the NAND Flash mtd Blackfin Driver and Interface, please follow this link:
-The NAND chip itself is not currently supported, please see [[http://blackfin.uclinux.org/pm/task.php?func=detailtask&project_task_id=520&group_id=17&group_project_id=74|this task]]) +
-</note> +
- +
- +
-For information about the NAND Flash mtd Blackfin Driver and Interface, +
-please follow this link:+
  
 [[linux-kernel:drivers:bfin_async_nand]] [[linux-kernel:drivers:bfin_async_nand]]