USB malfunction ?

Both in the datasheet and the mixer 1K5 between G+ pin and DISCONnect pin, pins 79 and 1 ,of 80. Desoldering it and DISCON goes high but not D+ now, so will have to retry connecting pc to mixer

G+ -------> D+

that 1K5 will have to go back in , It is the first point of recognition for USB linking. Next to find why DISCON is permanently H.

On Wed, 5 May 2010 08:56:58 +0100, "N_Cook" put finger to keyboard and composed:

My understanding is that the pullup resistor on D+ signals to the host (your PC) that a USB device has been plugged in. The host then attempts to enumerate (ie identify) the device.

If the device takes too long to go through its POST and initialisation routines, then the host may time out. In such cases the device may implement an active pullup which is disabled during its POST. When the device is ready, the pullup resistor is enabled, allowing enumeration to begin.

AIUI, the normal state of DISCON# is high.

See this EZ-USB Development Board (circuit on pages 5 & 6):

I found this detailed document:

The EZ-USB USB Integrated Circuit Technical Reference:

It states that EZ-USB devices can power up in RAM-only mode, in which case the host downloads runtime code into the 8051 CPU's internal 8K RAM. During this time the device identifies itself as a "Default USB Device". After the code has been downloaded, the device disconnects and then reconnects, this time renumerating as the device defined within the downloaded code.

Page 41 describes the EA (external access) pin. I think this may be the key to how the device behaves. The tech ref also talks about mask ROMed versions. Perhaps there is a way to force the EZ-USB chip into RAM-only mode??? If so, then this will remove any corrupt firmware from the equation. You could then use UVCView to see how the device enumerates under these circumstances.

You could also disconnect the serial EEPROM, if any. The EEPROM would contain Product and Vendor IDs for the manufacturer of the mixer. If the EEPROM is absent, then the EZ-USB chip will ID with the PID and VID of 0x0547 (Cypress Semiconductor) and 0x2131 (EZ-USB), respectively.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

for

That gives me a lot to look into next week , if it should be quiet. The other thing I cannot find is a "reverse" VID/PID lookup source . In this particular case the code for Event (maker) Ezbus (product) or perhaps subclass of "digital mixer" to find a www reference to what the Ezbus USB ident code should be. Confusingly Ezbus product uses Ez-usb chip.

On Sat, 8 May 2010 09:57:29 +0100, "N_Cook" put finger to keyboard and composed:

The PID and VID should be in the INF file in the driver / firmware updater, EzBus.inf.

[DeviceList] %DESCRIPTION0%=DriverInstall,USB\VID_0B45&PID_0000 %DESCRIPTION1%=DriverInstall,USB\VID_0B45&PID_0001&MI_04

DESCRIPTION0="EZbus - Needs firmware refresh" DESCRIPTION1="EZBus Control Surface Engine"

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

I'm a late developer at this sort of stuff. I'd downloaded that Event1 stuff but not unzipped it / run it and would not have expected that info there anyway. I would have thought that would be in a higher/lower? level of maker masked/loaded ROM or PROM not potentially user eraseable EEPROM . So the problem now looks less daunting and explains why the situation can arise of corrupted upload/ blocked reload/ dead kit.

As I type, a moulded (to be perforated) guard band to go over the 0.8mm pin spacing 80 pin EZ-usb chip is just cooling down so I can safely probe with scope/Thurlby DSA524/ Thurlby LA160 etc. I should say cooling down over an

80 pin HD61602 LCD driver chip as a matching plug or mould or whatever the casting term is. The 2 memory devices are a bit more approachable

Taken some readings (not repeated so maybe not pin for pin correct) EZ-bus post-POST situation Logical Analyser LA160 not used yet pin /function * DVM "volts DC" (steady av voltage of pulse train ) * scope trace

1 DISCON# * 3.3 2 VCC * 3.3 3 GND * 0 4 CLK24 * 1.6 * 23.997MHz 5 GND * 0 6 GND * 0 7 A0 * 1.5 * high speed data 8 A1 * 1.5 * high speed data 9 A2 * 1.5 * high speed data 10 A3 * 1.4 * high speed data 11 A4 * 1.7 * high speed data 12 A5 * 1.5 * high speed data 13 GND * 0 14 GND * 0 15 A6 * 1.4 * 40uS word length data 16 A7 * 1.2 * 40uS word length data 17 GND * 0 18 AGND * 0 19 XIN * 1.4 20 XOUT * 1.4 21 AVCC * 3.3 22 VCC * 3.3 23 GND * 0 24 EA * 0 25 RESET * 0 26 A8 * 2.3 27 A9 * 0.7 28 A10 * 1 29 A11 * .5 30 PC0/RxD0 * 5 31 PC1/TxD0 * 3.3 32 PC2/INT0# * .08 33 PC3/INT1# * 5 34 A12 * 1.2 * 40uS word length data 35 A13 * .5 * 40uS word length data 36 A14 * .5 * 40uS word length data 37 A15 * .6 * 40uS word length data 38 PC4/T0 * 0 39 PC5/T1 * 3.3 40 PC6/WR# * 3.2 41 PB7/T2out *3,3 42 VCC * 3.3 43 GND * 0 44 PB0/T2 * 0 45 PB1/T2EX * 0 46 PB2/RxD1 * 5 47 PB3/TxD1 * 3.3 48 D0 * .6 * 40uS word length data, 3 level 49 D1 * .7 * 40uS word length data, 3 level 50 D2 * .5 * 40uS word length data, 3 level 51 D3 * .5 * 40uS word length data, 3 level 52 PB4/INT4 * 5 53 PB5/INT5# * 5 54 PB6/INT6 * .07 55 PC7/RD# * .07 56 GND * 0 57 D4 * 1.8 * 40uS word length data, 3 level 58 D5 * .4 * 40uS word length data, 3 level 59 D6 * .9 * 40uS word length data, 3 level 60 D7 * 1.8 * 40uS word length data, 3 level 61 BKPT * 0 62 VCC * 3.3 63 GND * 0 64 SDA * 3.3 65 SCL * 3.3 66 WAKEUP# * 3.3 67 NC * 0 68 PA0/T0out * 3.3 69 PA1/T1out * 0 70 PA2/OE# * 0 71 PA3/CS# * 2.9 72 GND * 0 73 PA4/FWR# * 3.3 74 PA5/FRD# * 3.3 75 PA6/RXD0out * 5 76 PA7/RXD1out * 0 77 USBD- * .04 78 GND * 0 79 USBD+ * 3.3 80 PSEN# * 2.9 * 40uS word length data

24LC128 EEPROM voltages

1, A0, always H 2, A1 ,always L 3, A3 ,always L 4, Vss, 0V 5, SDA, data burst at switch on , about 2sec gap, then burst post POST 6, SCL, clock bursts as p5 7,WP , L 8 , Vcc, 3.3V

SCL bursts, from scope, bit less than100KHz, datasheet says 90.9 KHz I intend firstly reading and storing on disc, the SDA stream but have lost the LA160 to pc RS232 lead so will have to make another one first