What use really has the jumper J1?

wuxx / icesugar

iCESugar FPGA Board (base on iCE40UP5k)

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What use really has the jumper J1? #29

Closed juanmard closed 3 years ago

juanmard commented 3 years ago

Pin 35 from FPGA is an output from internal PLL (ICE_CLK), so is an input on microcontroller STM32 (as a clock?). Why need a jumper here? What is it used for?

imagen

wuxx commented 3 years ago

the MCU output 12MHz clock to iCE40 as external clock, but if you need other frequence, you can take off the jumper and connect your specified clock source.

juanmard commented 3 years ago

Thanks!