Bora YILDIZ

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9 years, 3 months ago.

Missing TGT_SWO in Schematics for LPC1768

I have a bit confused about TGT_SWO net. In the schematics I couldn't find any point that "TGT_SWO" net connected. I think this net should be connected to pin18 in LPC11U35FHI33/501. In the LPC11U pin18(TGT_SWO) seems NC. Are there any missing in schematics?

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Last updated: 30 Apr 2020
Board, board design, board layout, custom board, custom hardware, HDK, PCB, Production

1 Answer

Wim Huiskamp
9 years, 3 months ago.

The original mbed lpc1768 does not use an lpc11u35 as the interface chip. Instead it uses an unidentified IF processor (also NXP ARM device) which uses a netname TGT_TDO for the SWO pin 1 from the lpc1768 to the IF. See schematic mbed-005.1.pdf

The more recent Seeed studio Arch_Pro mbed lpc1768 does use the lpc11u35 interface and the TGT_SWO from lpc1768 is connected to pin 18 of the 11u35.

Accepted Answer

Thanks Wim, In the recent "mBed-HDK" file, LPC11U35 pin18 seems not connected. So, I guess there is a little missing in the schematics.

Also WAKE_NREQ(pin26) and SLEEP_NREQ(pin27) are not connected. But they should be already like this if I am not wrong.

posted by Bora YILDIZ 07 Jan 2015