11.3.3.1 Crossbar Functional Map
The figure below shows all of the potential peripheral-to-pin assignments available to the crossbar. Note that this does not mean any
peripheral can always be assigned to the highlighted pins. The actual pin assignments are determined by the priority of the enabled
peripherals.
UART1-TX
1
UART1-RX
1
SYSCLK
PCA0-CEX0
PCA0-CEX1
PCA0-CEX2
PCA0-ECI
Timer0-T0
Timer1-T1
0
1
2
3
4
5
6
7
P0
Port
Pin Number
0
0
0
0
0
0
0
0
P0SKIP
Pin Skip Settings
SPI0-SCK
SPI0-MISO
SPI0-MOSI
SPI0-NSS
2
0
1
2
3
4
5
6
P1
0
0
0
0
0
0
0
P1SKIP
The crossbar peripherals are assigned in priority order from top to bottom.
These boxes represent Port pins which can potentially be assigned to a peripheral.
Special Function Signals are not assigned by the crossbar. When these signals are
enabled, the Crossbar should be manually configured to skip the corresponding port pins.
Pins can be “skipped” by setting the corresponding bit in PnSKIP to 1.
Notes:
1. UART1 pins are available in these locations to be backwards compatible with UART0 on
other devices. UART1 is available either in the fixed P0.4 and P0.5 locations or the
standard UART1 crossbar locations. The pins should not be enabled in both locations at the
same time.
2. NSS is only pinned out when the SPI is in 4-wire mode.
SMB0-SDA
SMB0-SCL
QSOP-24 Package
VREF
EXTCLK
CNVSTR / CLU2OUT
AGND
Timer2-T2
CMP0-CP0
CMP0-CP0A
CMP1-CP1
CMP1-CP1A
0
1
P2
UART1-TX
UART1-RX
UART1-RTS
UART1-CTS
QFN-24 Package
C2D
CLU3OUT
CLU1OUT
CLU0OUT
QFN-20 Package
N/A
N/A
N/A
N/A
Pi
ns Not A
vailable on
Crossbar
VBUS
C2D
Figure 11.4. Full Crossbar Map
EFM8UB3 Reference Manual
Port I/O, Crossbar, External Interrupts, and Port Match
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