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tigard-tools / tigard

An FTDI FT2232H-based multi-protocol tool for hardware hacking
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R22 #62

Closed fy2002 closed 1 year ago

fy2002 commented 1 year ago

image what is resistor r22 2k2 for? It seems that net BD7 connected to nothing.

securelyfitz commented 1 year ago

That's for using iceprog to progam ice40 fpgas. It uses the BDBUS7 as the ICE_CRESET output and does not use BDBUS5 at all. Since we're limited on output pins and already have BDBUS5 as jtag/swd reset, we tie them together with the 2k2 resistor so that BD7 only affects the output when BD5 is high-z. See #15