Datasheet

 2015 Microchip Technology Inc. DS20005292B-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
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 R
X 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 T
X 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
configured, 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
voltage)
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 V
DD
Bits 4-0: Power-Up DAC value