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USB low-full-high speed peripherals Forum Discussions

JeWa_4510716
Level 1
Level 1

Hello,

I'm having problems with mounting USB flash drive in this host controller.  It works most of the time but occasionally does not.  I noticed the times it is not mounting is at booting up embedded device.

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1 Solution
YatheeshD_36
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hello,

The embedded system should monitor the EZ-Host for the ready signalling (after the code is loaded on to the EZ-Host RAM).

EZ-Host then waits for a command sequence to start which should be issued from the SPI master. The command sequence is to start the EZ-USB code through a JUMP instruction.

Please make sure that this is being met.

If there is any failure during initialization, the embedded system/processor should reset the EZ-Host and monitor for the Ready signalling before performing the required operations.

Thanks,

Yatheesh

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YatheeshD_36
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hello,

The embedded system should monitor the EZ-Host for the ready signalling (after the code is loaded on to the EZ-Host RAM).

EZ-Host then waits for a command sequence to start which should be issued from the SPI master. The command sequence is to start the EZ-USB code through a JUMP instruction.

Please make sure that this is being met.

If there is any failure during initialization, the embedded system/processor should reset the EZ-Host and monitor for the Ready signalling before performing the required operations.

Thanks,

Yatheesh

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Thanks for your quick reply.  I am resetting three pins of microprocessor that connect to USB host controller, and it does not seem to help with this problem.  It looks like correct place to reset as I notice like on flash drive light go on and off and then blink.  But there are times when host controller seems completely dead and I don't see light on flash drive go off and back on or blink at all.  The light just stays on and then no response from the "ready" command.

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Hello,

Is the EZ-Host not responding to the SPI commands after it signals the micro-processor that its Ready?

Can you please probe the SPI and the GPIO signals between the EZ-Host and the microprocessor and check if the SPI initialization commands are sent after the Ready signal Pin goes low? Please make sure that the GPIO is low atleast for 100us before the SPI master initiates the commands.

Thanks,

Yatheesh

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No, I get no response from the host controller chip sometimes on device bootup.  It is supposed to serially send back the "ready" characters, but no response.   And it doesn't respond to a reset. 

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Hello,

Did you try probing the Signals on the interface and see if there is any activity?

Thanks,

Yatheesh

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No, how would you do that? 

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Hello,

The GPIO25 will signal the SPI master that the content from the EEPROM is loaded on to the SRAM by driving the signal Low. While the code is loading the GPIO will signal high.

Then the SPI master can start the code through an LCP command when it detects a low on the GPIO line.

Please refer to the Initialization Sequence Section in this Application note: https://static5.arrow.com/pdfs/2011/1/9/22/55/18/43/cyp_/manual/an15484.pdf 

Can you please confirm this conditions are met before SPI transactions are started. You can use a logic analyzer to probe the interface signals.

Thanks,

Yatheesh

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I don't think we're connecting through SPI interface.   USB controller is connected to I/O Port 3 of 80C188EB processor(powers usb controller) and serial port(sends Rx and Tx commands) to host chip.

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Hello,

Can you please provide complete details of your application and also the base document that you have referred to for your firmware and application?

Thanks,

Yatheesh

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