Datasheet

 2014 Microchip Technology Inc. DS20005292A-page 19
MCP2221
1.7.1.4 LED_URX
The ‘RX’ in this pin name refers to the UART of the
MCP2221. The LED_URX pin is an indicator of UART
R
X characters being received.
This pin will pulse low or high (depending on the chip
configuration settings, see CHIPSETTING0 register for
details) for a period of time (a few milliseconds). This
allows the application to provide a visual indication of
UART R
X traffic.
1.7.1.5 LED_UTX
The ‘TX’ in the pin name refers to the UART of the
MCP2221. The LED_UTX pin is an indicator of UART
T
X characters being transmitted.
This pin will pulse low or high (depending on the chip
configuration settings, see CHIPSETTING0 register for
details) for a period of time (a few milliseconds). This
allows the application to provide a visual indication of
UART T
X traffic.
1.7.1.6 LED_I2C
The ‘I2C’ in the pin name refers to the I
2
C module in the
MCP2221. The LED_I2C pin is an indicator of I
2
C activ-
ity.
This pin will pulse low or high (depending on the chip
configuration settings, see CHIPSETTING0 register for
details) for a period of time (a few milliseconds). This
allows the application to provide a visual indication of
I
2
C traffic.
1.7.1.7 ADC1/2/3
When GP1/2/3 are configured for ADC operation, they
will work as analog input pins and they are tied to the
first three channels of the 10-bit ADC in the MCP2221.
1.7.1.8 DAC1/2
When GP2/3 are configured for DAC operation, they
will work as analog output pins and they are tied to the
output of the MCP2221’s 5-bit DAC.
TABLE 1-5: GP DESIGNATION TABLE
GP
Designation
Bits <2:0>
Assignment GP0 GP1 GP2 GP3
000 GPIO GPIO GPIO GPIO GPIO
001 DEDICATED_FUNC SSPND CLK OUT USBCFG LED_I2C
010 ALT_FUNC_0 LED_URX ADC1 ADC2 ADC3
011 ALT_FUNC_1 — LED_UTX DAC1 DAC2
100 ALT_FUNC_2 — IOC — —