C8051F540-TB Silicon Laboratories Inc, C8051F540-TB Datasheet - Page 149

• Manufacturer Part Number: C8051F540-TB
• Description: BOARD PROTOTYPE W/C8051F540
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F540-TB

• Contents: Board
• Processor To Be Evaluated: C8051F54x
• Processor Series: C8051F54x
• Interface Type: USB
• Operating Supply Voltage: 5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: C8051F54x
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1672

18.1.3. Interfacing Port I/O in a Multi-Voltage System
All Port I/O are capable of interfacing to digital logic operating at a supply voltage higher than V
than 5.25 V. Connect the V
18.2. Assigning Port I/O Pins to Analog and Digital Functions
Port I/O pins P0.0–P3.0 can be assigned to various analog, digital, and external interrupt functions. The
Port pins assigned to analog functions should be configured for analog I/O, and Port pins assigned to digi-
tal or external interrupt functions should be configured for digital I/O.
18.2.1. Assigning Port I/O Pins to Analog Functions
Table 18.1 shows all available analog functions that require Port I/O assignments. Port pins selected for
these analog functions should have their corresponding bit in PnSKIP set to 1. This reserves the pin
for use by the analog function and does not allow it to be claimed by the Crossbar. Table 18.1 shows the
potential mapping of Port I/O to each analog function.
18.2.2. Assigning Port I/O Pins to Digital Functions
Any Port pins not assigned to analog functions may be assigned to digital functions or used as GPIO. Most
digital functions rely on the Crossbar for pin assignment; however, some digital functions bypass the
Crossbar in a manner similar to the analog functions listed above. Port pins used by these digital func-
tions and any Port pins selected for use as GPIO should have their corresponding bit in PnSKIP set
to 1. Table 18.2 shows all available digital functions and the potential mapping of Port I/O to each digital
function.
ADC Input
Comparator0 or Compartor1 Input
Voltage Reference (VREF0)
External Oscillator in Crystal Mode (XTAL1)
External Oscillator in RC, C, or Crystal Mode (XTAL2)
*Note: P2.2-P2.7, P3.0 are only available on the 32-pin packages
UART0, SPI0, SMBus, LIN0,
CP0, CP0A, CP1, CP1A,
SYSCLK, PCA0 (CEX0-5
and ECI), T0 or T1.
*Note: P2.2-P2.7, P3.0 are only available on the 32-pin packages.
Digital Function
Analog Function
Table 18.1. Port I/O Assignment for Analog Functions
Table 18.2. Port I/O Assignment for Digital Functions
IO
pin to the voltage source of the interface logic.
Any Port pin available for assignment by the
Crossbar. This includes P0.0–P3.0* pins which
have their PnSKIP bit set to 0.
Note: The Crossbar will always assign UART0 pins
to P0.4 and P0.5.
Potentially Assignable Port Pins
Rev. 1.1
Potentially Assignable
P0.0–P3.0*
P0.0–P2.7*
Port Pins
P0.0
P0.2
P0.3
C8051F54x
XBR0, XBR1, XBR2
CPT0MX, CPT1MX,
OSCXCN, PnSKIP
OSCXCN, PnSKIP
ADC0MX, PnSKIP
REF0CN, PnSKIP
SFR(s) used for
SFR(s) used for
Assignment
Assignment
PnSKIP
DD
and less
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