Why PIO0_1 pin has no external pull-up device ?

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by noritan_org on Tue Feb 09 06:06:50 MST 2010
The LPC111x user manual UM10398 Rev.00.10 says in the page 220

Pin PIO0_1 that is used as hardware request for ISP requires special attention.
Since PIO0_1 is in high impedance mode after reset, it is important that the user provides
external hardware (a pull-up resistor or other device) to put the pin in a defined state.
Otherwise unintended entry into ISP mode may occur.

But the LPCXpresso board has no external component on PIO0_1 pin.

Why is the board is working ?
Someday, sometimes, is ISP invoked ?