Hi,
A friend of mine gave me the Memec Design's DS-BD-V4LX25LC FPGA board. It has a Xilinx's Vertex 4 XC4VLX25 on it. He doesn't have the schematic anymore and I also can't find anything on the web. Does anyone know where I can get a copy?
Thanks,
James
Hi,
My company makes a portable device (battery operated). If we connect the device's USB port to a PC while it sits on the charger, sometimes device resets, sometimes the PC reset, sometimes both reset.
I think the problem is caused by the voltage differential between the grounds of the two...
Hi,
On my existing design, the Processor's External Bus Interface (EBI) is currently interfacing to a SDR SDRAM chip. The bus runs on 1.8V @ 130 MHz. Now, I need to add a device to the EBI, but unfortunately, this device requires 3.3V to run. Besides the obvious level translation IC, do I...
Hi,
I have a USB OTG capable device. Unfortunately, the USB ID pin is not brought out to the connector (it's floating). Is the USB ID pin required for OTG function? Let's suppose my device somehow knows the Host/Device role it is supposed to be (by other means), would USB OTG function, in...
Hi,
We have an old Processor, which have a hardware support 1-bit ECC NAND Flash.
We now have to upgrade our NAND Flash IC and unfortunately, almost all newer NAND Flash ICs require 4-bit ECC.
How does our Processor, which only have 1-bit ECC support, work with a 4-bit ECC NAND Flash part...
Hi,
I am doing a design with DDR memory and I need to simulate the signal integrity of the PCB layout. Yes, I have never done SI check for the DDR memory before, so I don't know anything...
How do I find out the information such as voltage requirements (overshoot, undershoot, etc), timing...
Hi everyone,
I have a processor board which has a power input and a SPI port at its external interface. The SPI port is connected directly to the processor.
What could happen to the processor if I just connect up the SPI port and apply a logic high to it without providing power to the...
Hi,
When our device is powered off while writing to a NAND flash, the firmware in the NAND Flash is corrupted and prevents the device from ever powering up again. Is there any application note or tips to fix this problem?
Thank you in advance!
James
Hi,
I would like to measure the eye-diagram of the DDR's clock. What do the oscilloscope probe connections look like in order to display the eye-diagram?
Also, the DDR clock is 133MHz, what's the required oscilloscope bandwidth? If I use a 2pF FET probe to probe the clock, will it be OK...
Hi,
The SCLK of the SDR SDRAM on my layout looks like a sine wave! Its rise and fall times are so slow that there is not enough time for the required high or low timing.
There is only one SDRAM chip on the design. The clock line length is about 3 inches. I already use maximum drive strength...
Hi everyone,
I have a 12MHz, 0.8Vpp clip sine wave coming from a VCO and I need to square up this signal to TTL-compatible logic. The TI's CDC3RL02 can do the conversion, but its output is only 1.8V. I will need another level converter to convert it to 3.3V.
Is there any IC out there that...
Hi,
I have an AC clipped sine clock with an amplitude of 1Vpp @ 15 MHz. I need to convert this signal to a TTL-compatible signal. What's the best way to do this?
Regards,
James
Hi,
For Speaker Volume control, do we typically control Volume Knob voltage in linear scale (Volt) against the gain of the speaker Amp in log scale (dB)? In other words, is there typically a logarithmic relationship between the volume knob and the speaker volume?
Thank you in advance...
Hello everyone,
How do I calculate the throughput of SRAM, SDR and DDR SDRAM? Is there a formula to calculate it?
Let suppose that:
- The speed for all three memory ICs = 100 MHz
- Data width = 16
- SRAM is attached to Asynchronous Memory Interface
- SDR and DDR SDRAM (both CL2) are connected...
Hello all,
Would someone please explain why there an ESD discharge to a phone lying on a _wooden_ table?
For what I understand, electrical current only flows when there is a closed electrical path. With the phone lying on a wooden table, how does the ESD (from an ESD gun or from a person)...
Hi everyone,
I implemented a battery protection circuit as suggested by the S-8242B protection IC's datasheet and ran into a problem. I then simulated the circuit in LTspice and confirmed that the problem actually exists.
As shown in the attached picture, the two back-to-back N MOSFET are...
Hi,
I am using a DAC to control the voltage applied to "Iset" of a white LED driver IC (Onsemi CAT4104). Unfortunately, the DAC does not have enough current driving capability the CAT4104 requires (about 1mA).
I think I will need a buffer for the DAC. An Op-Amp buffer will do the job, but I...
Hi everyone,
Is NAND Flash an asynchronous or synchronous memory? How can I tell?
From what I understand, synchronous memory requires a clock signal, but there isn't seem to be one on a NAND Flash... I could be wrong, though.
No, this is not a homework question.
Regards,
James
Hi everyone,
Many vendors claim that they have very low power CPLD. Is there any benchmark on who has the lowest power consumption? I am looking at the CPLD with about 75 I/O or so.
Best regards,
Hai
Hi everyone,
How do I determine the wait-state of the external flash memory to a processor (ADI blackfin). What characteristic of the CPU or external flash determine the wait-state? Thank you very much in advance!
James
