PRELIMINARYCY7C656xx
8.0Default Descriptors
8.1Device Descriptor
The standard device descriptor for CY7C656xx is based on the VID, PID, and DID found in the SPI EEPROM. This VID/PID/DID in the EEPROM will overwrite the default VID/PID/DID. If no EEPROM is used, the CY7C656xx will enumerate with the default descriptor values as shown below.
Byte | Full Speed | High Speed | Field Name | Description |
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0 | 0x12 | 0x12 | bLength | 18 Bytes |
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1 | 0x01 | 0x01 | bDescriptorType | DEVICE_DESCRIPTOR |
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2,3 | 0x0110 | 0x0200 | bcdUSB | USB specification 2.0 in HS (1.1 if forced FS) |
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4 | 0x09 | 0x09 | bDeviceClass | HUB |
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5 | 0x00 | 0x00 | bDeviceSubClass | None |
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6 | 0x00 | 0x01[4]/ 0x02[5] | bDeviceProtocol | None |
7 | 0x40 | 0x40 | bMaxPacketSize0 | 64 bytes |
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8,9 | 0x04B4 | 0xx04B4 | wIdVendor | VID (overwritten by what is defined in EEPROM) |
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10,11 | 0x6560 | 0x6560 | wIdProduct | PID (overwritten by what is defined in EEPROM) |
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12, 13 | 0x0910 | 0x0910 | wbcdDevice | DID (overwritten by what is defined in EEPROM) |
| 0x0810 | 0x0810 |
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14 | 0x00 | 0x00 | iManufacturer | No manufacturer string supported |
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15 | 0x00 | 0x00 | iProduct | No product string supported |
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16 | 0x00 | 0x00 | iSerialNumber | No serial string supported |
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17 | 0x01 | 0x01 | bNumConfigurations | One configuration supported |
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8.2Configuration Descriptor
Byte | Full Speed | High Speed | Field Name | Description |
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0 | 0x09 | 0x09 | bLength | 9 Bytes |
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1 | 0x02[7]/ 0x07[8] | 0x02[7]/ 0x07[8] | bDescriptorType | CONFIG_DESCRIPTOR |
2 | 0x0019 | 0x0019[4] | wTotalLength | Length of all other descriptors |
| 0x0029 | 0x0029[5] |
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4 | 0x01 | 0x01 | bNumInterfaces | 1 |
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5 | 0x01 | 0x01 | bConfigurationValue | The configuration to be used |
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6 | 0x00 | 0x00 | iConfiguration |
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7 | 0xA0 | 0xA0 | bmAttributes | Value depends on pin 45 - SELFPWR signal |
| 0xE0 | 0xE0 |
| SELFPWR = 0 yields 0xA0 and =1 yields 0xE0 |
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8 | 0x28 | 0x57[6] | bMaxPower |
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8.3 | Interface Descriptor |
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Byte |
| Full Speed | High Speed | Field Name | Description |
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0 |
| 0x09 | 0x09 | bLength | 9 Bytes |
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1 |
| 0x04 | 0x04 | bDescriptorType | INTERFACE_DESCRIPTOR |
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2 |
| 0x00 | 0x00 | bInterfaceNumber |
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3 |
| 0x00 | 0x00 | bAlternateSetting |
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4 |
| 0x01 | 0x01 | bNumEndpoints |
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5 |
| 0x09 | 0x09 | bInterfaceClass |
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6 |
| 0x00 | 0x00 | bInterfaceSubClass |
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7 |
| 0x00[4]/ 0x01[5] | 0x00[4]/ 0x01[5] | bInterfaceProtocol |
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| 0x00 | 0x00 | iInterface |
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Notes: |
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4.If configured as
5.If configured as
6.This value is configured through the External EEPROM.
7.Configured speed descriptor
8.Other speed descriptor
Document #: | Page 10 of 23 |
