The CY7C65642-28LTXCT

[NoAr_1540581]

Hello

Q1)Regarding the bMax-power, it is described on page 14 of the datasheet, but we are understanding that it is necessary to set the Maximum Power value for each connected "devices"?

If no, please tell me the details.

Q2-1) The default value is described as "32h(100 mA)", but please tell me the reason.

Q2-2)When powering HX2VL with self power, is it possible to change the bMax-power descriptor
information by themselves to FAh(500 mA)?If yes, is it possible to change the bMax-power value of EEPROM directly?

Best Regards

Arai

[HirotakaT_91 · Accepted solution]

Hi Arai-san,

Q1) It is NOT possible to set the MaxPower value to each connected "device".

Instead, each device will have its own MaxPower value which will be indicated to the host through its descriptors.

Q2-1) The default value is indicated as 100mA which is intended for Self-Powered Hub.

For Bus-Powered Hub, it needs to be set as 500mA (FAh) to accommodate 100mA for each downstream device (4 x 100mA) + Hub power consumption (100mA).

Q2-2) It is recommended to set MaxPower value to 500mA if the application requires switching between Bus-Powered and Self-Powered modes.

It is possible to change the MaxPower value with the help of external EEPROM through Blaster Utility. To use Blaster utility, Hub needs to be bound to Vendor driver.

Best regards,

Hirotaka Takayama