Mpc5200 and ISP1106/1107 USB transceivers

[Zeitler, Nathan]

 > Url: http://ozlabs.org/pipermail/linuxppc-embedded/attachments/20050805/a2aa0d78/attachment-0001.eml

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Seems that Philips has put out an errata not too long ago for this 
chip which isn't in any public errata document that we could find.  
Here's how it reads:

Problem: 
With the ISP1105/6 used as a Universal Serial Bus (USB) 
transceiver in a Host Controller application, when a low-speed 
device is connected, it does not get enumerated. Full-speed 
devices, however, are properly enumerated.

When pin OE_N goes HIGH, the ISP1105/6 must be in receive 
mode and the DM line should be detected as HIGH because of 
the pull-up resistor on the D− line in the case of the low-speed 
device. But in the ISP1105/6, the D− line rises very slowly, taking 
almost 30 ms. This affects enumeration.

Workaround:
In the ISP1105, the problem can be resolved by ORing VO with 
OE_N to produce VO to the ISP1105. This is applicable when 
the MODE pin is configured as LOW; single-ended input data 
interface. 

This circuit will ensure that VO is held HIGH till OE_N is HIGH, 
ensuring that the compensation logic is not turned on.

In the ISP1106, this must be implemented by ANDing OE 
(inverted OE_N) with VMO to produce VMO to the ISP1106.


Nathan Zeitler
Hardware Engineer
Open Systems International, Inc.
3600 Holly Lane North, Suite 40
Minneapolis, MN 55447-1286
Phone: (763) 551-0559
Fax:     (763)551-0750
Email:  nzeitler at osii.com