LPC81XM ISP RXD Pin

[ductio_aj]

The data sheet for LPC81x defines pin 19 "In ISP mode, this is the USART0 receive pin U0_RXD.
In boundary scan mode: TDO (Test Data Out)"

But the schematic of LPC812MAX target RX is connected to pin 18.

What are the correct pins to connect the ISP UART to?

[ZhangJennie]

Hi

I don't know where is the misunderstanding but both schematic and datasheet are correct.

I checked datasheet, U0_RXD is pin 19

https://www.nxp.com.cn/docs/en/data-sheet/LPC81XM.pdf

In ISP mode, pin PIO0_0 is connected to function U0_RXD and pin PIO0_4 is connected to function U0_TXD on the USART0 block.

ZhangJennie_0-1634798807443.png

In LPC812 MAX board, the connection is the same as schematic.

ZhangJennie_1-1634799055367.png

ZhangJennie_2-1634799828366.png

Have a nice day,

Jun Zhang