EVK-IRIS-W10 - User guide
UBX-23007837 - R03
Hardware description
Page 24 of 43
C1-Public
Figure 25: jumpers default connections
Figure 26: External JTAG debug interface demultiplexing
3.7
32.768 kHz low frequency clock
The evaluation board has a
32.768 kHz
crystal connected to the IRIS-W10 module that allows
use of the external crystal oscillator option to source the RTC clock which is
not
enabled by
default.
GPIO21
and
GPIO23
multiplex some of the RMII signals and the external crystal oscillator
shows how to demultiplex those GPIOs.
To enable low frequency clock, populate
R267, R271
with
0R
and disconnect
R268, R269,
R272, R273
.
Figure 27: Schematic – 32 kHz crystal
J15
GPIO6_U1-CTS-CS_JTAG-TCK
J34
GPIO7_U1-CLK_JTAG-TMS
J35
GPIO8_U1-TxD-MISO-SCL-WS_JTAG-TDI
J36
GPIO9_U1-RxD-MOSI-SDA-TRX_JTAG-TDO
J37
GPIO10_U1-RTS_JTAG-nRST
GPIO6_U1-CTS-CS
GPIO7_U1-CLK
GPIO8_U1-TxD-MISO-SCL-WS
GPIO9_U1-RxD-MOSI-SDA-TRX
GPIO10_U1-RTS
JTAG-TCK
JTAG-TMS
JTAG-TDI
JTAG-TDO
RESETn
