Datasheet

 2014 Microchip Technology Inc. DS20005292A-page 53
MCP2221
3.1.14 GET SRAM SETTINGS
This command is used to retrieve the runtime Chip and
GP settings.
3.1.14.1 Responses
TABLE 3-38: COMMAND STRUCTURE
Byte
Index
Value Effect
0 0x61 Get SRAM Settings – command code echo
1-63 0x00 Command completed successfully
TABLE 3-39: RESPONSE 1 STRUCTURE
Byte
Index
Function Description Value Effect
0 0x61 Get SRAM Settings – command code echo
1 0x00 Command completed successfully
2 Length in bytes of the SRAM Chip-set-
tings area.
3 Length in bytes of the SRAM GP set-
tings area.
4 Bit 7: CDC Serial Number Enumeration
Enable
1 The USB serial number will be used during the USB
enumeration of the CDC interface
0 No serial number descriptor will be presented during
the USB enumeration
Bit 6: Initial value for LEDUARTRX pin
option
This value represents the logic level signaled when no
UART RX activity takes places. When the UART RX (of
the MCP2221) is receiving data, the LEDUARTRX pin
will take the negated value of this bit.
Bit 5: Initial value for LEDUARTTX pin
option.
This value represents the logic level signaled when no
UART TX transmission takes place. When the UART
TX (of the MCP2221) is sending data, the LEDUARTTX
pin will take the negated value of this bit.
Bit 4: Initial value for LEDI2C pin option This value represents the logic level signaled when no
I
2
C traffic occurs. When I
2
C traffic is active, the LEDI2C
pin (if enabled) will take the negated value of this bit.
Bit 3: Initial value for SSPND pin option This value represents the logic level signaled when the
device is not in Suspend mode. Upon entering Suspend
mode, the SSPND pin (if enabled) will take the negated
value of this bit.
Bit 2: Initial value for USBCFG pin
option
This value represents the logic level signaled when the
device is not USB configured. When the device will be
USB configured, the USBCFG pin (if enabled) will take
the negated value of this bit.
Bit 1-0: Chip configuration security
option
10 Permanently locked
01 Password protected
00 Unsecured
5Bit 7-5 Don’t
care
Bit 4-0: Clock Output divider value If the GP pin (exposing the clock output) is enabled for
clock output operation, the divider value will be used on
the 48 MHz USB internal clock and its divided output
will be sent to this pin.