I'm designing a general-purpose PCB for a 8051-family MCU. I make it compatible to use shields for the Arduino Uno. There is a snag with the reset circuitry, as an Arduino is active-low reset and the 8051 is active-high reset. So if a shield has a reset button I need to feed it to the 8051 MCU through a logic inversion.
In the schematic, J1 is the Dupont connector to the shield. Disregard J8 as it is an unrelated external connector for a reset button and power-on LED. R2 and D1 is just a power indicator.
The net labelled "RST" is the 8051 reset pin; R1/C1/SW1 is the standard reset circuitry for 8051 MCUs; R10 limits current from C1 discharge, and SW1 is an on-board reset button.
Net labelled "RESET" could be wired to a reset button on an Arduino Uno shield. R9/R11/Q3 is the actual inverter that shunts C1 as would SW1 when the transistor base is pulled low from the shield's reset button.
Does everything seem ok?