USB malfunction ?
 

I know nothing of USB function other than what I've just read on
usb-in-a-nutshell.pdf
and the datasheet for Cypress AN2131QC USB chip .
I downloaded legacy installer.exe and firmware stuff from
http://www.event1.com/Support/EZbus/...s/firmware.htm
for an Ezbus digital mixer. Unzips and apparently functions on the pc.

Cannot connect PC to the Ezbus, to reload firmware, as not recognised
hotplugging USB and if plugged in before booting PC then it hangs the PC.
On mixer on its own, USB D+ line is low during POST and then goes to and
stays at 3.3V when presumed corrupted system code starts up. The main
controller hangs up at this point also (2 of the 3 clocks present but third
comes from a stuck high pin) and no function of any sort on the mixer .
Could corrupted sysyem code make the USB hang like that or could corrupt USB
chip hang the main control?
What to look at next?

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

USB malfunction ?
 

G+ ------- D+

USB malfunction ?
 

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.

USB malfunction ?
 

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

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.

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):
http://www.minford.ca/MF3001EZUSBManual.pdf

I found this detailed document:

The EZ-USB USB Integrated Circuit Technical Reference:
http://www.digchip.com/data/115/115-00027-0-AN2121S.pdf

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

USB malfunction ?
 

Franc Zabkar wrote in message
...
On Wed, 5 May 2010 08:56:58 +0100, "N_Cook" put
finger to keyboard and composed:

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.

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):
http://www.minford.ca/MF3001EZUSBManual.pdf

I found this detailed document:

The EZ-USB USB Integrated Circuit Technical Reference:
http://www.digchip.com/data/115/115-00027-0-AN2121S.pdf

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

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.

USB malfunction ?
 

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

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.

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

USB malfunction ?
 

Franc Zabkar wrote in message
...
On Sat, 8 May 2010 09:57:29 +0100, "N_Cook" put
finger to keyboard and composed:

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.

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
--
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

USB malfunction ?
 

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

USB malfunction ?
 

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