Driving a power mosfet with a gate driver w/ PWM toggle. When high, mosfet is expected to sink most of the current (current and voltage values in schematic are for testing purposes) through R1, however current does not change in 2nd branch (R3). Can someone explain this behavior?
Thanks.
It's just two resistors in parallel when the mosfet is open, so a simple I = V/R.
V3 s an ideal voltage source. The voltage doesn't change with the load. So R3 always will see the same voltage no matter if you switch on or off the MOSFET.
I(R3)=V3/R3
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I've implemented 32 bit rocket chip with rocc example, but in accumulator example while accessing data through hella cache interface using do_load instruction. The io_mem_response_valid signal remains high for two clock cycle so data in reg file is overwritten by data of next memory location.
vivado simulation waveform for simple do_load instruction
May be memory response interface default setting to transfer 64 byte or else. please assist me. how to change burst size?
Thanks & Regards,
Sanket
I just changed value of io.mem.req.bits.size = log2Ceil(4).U (i.e. 2) from https://github.com/chipsalliance/rocket-chip/blob/master/src/main/scala/tile/LazyRoCC.scala. which may informed response size for io.mem.resp interface.
I am driving external LEDs on my development board. I am using the Linux 'timer' trigger to blink them. However, the trigger allows the blinking of LEDs at a fixed rate. Is it possible to configure the rate at which the LEDs blink using the 'timer' trigger?
ledtrig-timer.c should provide delay_on and delay_off device files for the LED which can be used to set how long the LED is on and how long the LED is off.
Setting both of them to a small value will result in a fast flash rate.
Setting both of them to a small value will result in a slow flash rate.
Setting one longer than the other will result in varying "on" and "off" durations.
The LED Kernel Timer Trigger file ledtrig-timer.c is well commented and should help you figure out how to control the LEDs.
Note that the link is for an older 2.6 kernel, but it is better documented than the newer versions of the file.
I build a small game controller for the Z1.
I have a process reading values from a Joystick sensor. It works fine.
Then, I added a second process, reading the value of the battery sensor every 5 minutes. But it makes the Joystick stop working: the value does not update anymore!
I found a workaround: when I have to read the value of the battery, I deactivate the phidget_sensor, activate the battery_sensor, read the value and then deactivate the battery_sensor and reactivate the phidget_sensor.
But I would like to know why I can not have both sensors activated at the same time ?
Thanks
Comes from Here.
The ADC is the "analogue to digital converter", basically is the component that provides you the voltage signal levels of an analogue sensor, so then it can later be used to translate to a meaningful value.
What happens is the battery sensor driver and the phidget driver each when starts configures the ADC on its own, thus overwriting the ADC configuration.
The expected use of both of these components is actually how you are actually using: enable, measure, then disable. This way you ensure at all times the ADC is configured the way your application expects. If you want to have this done in a single operation then I'm afraid you will need to modify probably the phidget driver and include this.
I hope this is the answer you expected, as you are asking why does this happens.
I've been coding a 16-bit RISC microprocessor in Verilog, and I've hit yet another hurdle. After the code writing task was over, I tried to synthesize it. Found a couple of accidental mistakes and I fixed them. Then boom, massive error.
The design comprises of four 16-bit common buses. For some reason, I'm getting a multiple driver error for these buses from the synthesis tool.
The architecture of the computer is inspired by and is almost exactly the same as the Magic-1 by Bill Buzzbee, excluding the Page Table mechanism. Here's Bill's schematics PDF: Click Here. Scroll down to page 7 for the architecture.
The control matrix is responsible for handling when the buses and driven, and I am absolutely sure that there is only one driver for each bus at any given instance. I was wondering whether this could be the problem, since the synthesis tool probably doesn't know this.
Tri-state statements enable writing to a bus, for example:
assign io [width-1:0] = (re)?rd_out [width-1:0]:0; // Assign IO Port the value of memory at address add if re is true.
EDIT: I forgot to mention, the io port is bidirectional (inout) and is simply connected to the bus. This piece of code is from the RAM, single port. All other registers other than the RAM have separate input and output ports.
The control matrix updates a 30-bit state every negative edge, for example:
state [29:0] <= 30'b100000000010000000000000100000; // Initiate RAM Read, Read ALU, Write PC, Update Instruction Register (ins_reg).
The control matrix is rather small, since I only coded one instruction to test out the design before I spent time on coding the rest.
Unfortunately, it's illogical to copy-paste the entire code over here.
I've been pondering over this for quite a few days now, and pointing me over to the right direction would be much appreciated.
When re is low, the assign statement should be floating (driving Zs).
// enable ? driving : floating
assign io [width-1:0] = (re) ? rd_out [width-1:0] : {width{1'bz}};
If it is driving any other value then the synthesizer will treat is as a mux and not a tri-state. This is where the conflicting driver message come from.
I have an SPI signal output from a SPI device. I wonder why the data output (MOSI) goes to 0 half cycle before the actual data is written on the bus? Is it a must condition for an SPI device? If it does not go to zero, would there be any problem on the data transfer?
I use spidev32766.1 on linux (ubuntu 12.04 - kernel 3.7.1), the processor is imx233
Thank you in advance!!
The slave device doesn't care what happens on the data line except for a very short period (usually <1ns) either side of its active clock edge (this window is defined by the setup and hold time specifications for the interface).
I have no idea why your system would put out that "wiggle" though!