Datasheet

 2014 Microchip Technology Inc. DS20005292A-page 27
MCP2221
TABLE 3-5: RESPONSE STRUCTURE – READ CHIP SETTINGS SUB-COMMAND
Byte
Index
Function Description Value Effect
0 0xB0 Read Flash Data – command code echo
1 0x00 Command completed successfully
2 Structure length
3Don’t care
4 Bit 7: CDC Serial Number
Enumeration Enable
1 The USB serial number will be used during the USB enumer-
ation 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 the 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 config-
ured, the USBCFG pin (if enabled) will take the negated value
of this bit.
Bits 1-0: Chip configuration
security option
11-10 Permanently locked
01 Password protected
00 Unsecured
5 Bits 7-5 Don’t
care
Bits 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.
6 Bits 7-6: DAC Reference voltage
option
11 Reference voltage is 4.096V (only if V
DD is above this volt-
age)
10 Reference voltage is 2.048V
01 Reference voltage is 1.024V
00 Reference voltage is off (this is useful for the case in which
the DAC uses other reference than V
RM DAC; e.g., VDD).
Bit 5: DAC reference option 1 DAC reference is VRM DAC voltage
0 DAC reference is VDD
Bits 4-0: Power-up DAC value