Datasheet

MCP2221
DS20005292A-page 26  2014 Microchip Technology Inc.
3.1.2 READ FLASH DATA
This command is used to read various important data
structures and strings that are stored in Flash memory
on the MCP2221.
3.1.2.1 Responses
TABLE 3-3: COMMAND STRUCTURE
Byte
Index
Function Description Value Effect
0 0xB0 Read Flash Data – command code
1 Read Flash Data Sub-code.
The value in this field will instruct
the MCP2221 on what Flash
data to be read
0x00 Read Chip Settings – it will read the MCP2221 NVRAM
settings.
0x01 Read GP Settings – it will read the MCP2221.
0x02 Read USB Manufacturer Descriptor String – reads the
USB Manufacturer String Descriptor used during the USB
enumeration.
0x03 Read USB Product Descriptor String – reads the USB
Product String Descriptor used during the USB
enumeration.
0x04 Read USB Serial Number Descriptor String – reads the
USB Serial Number String Descriptor that is used during
USB enumeration. This serial number can be changed by
the user through a specific USB HID command.
0x05 Read Chip Factory Serial Number – reads the factory-set
serial number. This serial number cannot be changed.
Any other
value
No meaning. The device will reply with a code for an
unsupported command at Byte Index 1 in the Response
report.
2-63 Reserved 0x00
TABLE 3-4: RESPONSE STRUCTURE
Byte
Index
Function Description Value Effect
0 0xB0 Read Flash Data – command code
1 0x00 Command completed successfully
0x01 Command not supported
2 Data structure length or
Don’t care
3-63 Data or Don’t care Depends on the issued sub-command or the returned
code at Byte Index 1.