Since the PSoC input signals must be greater than 0V there was no need to design a negative voltage on the board. Only the UART-interface chip generates a negative voltage to be used for RS232, but that is not stabilized.
What do you need negative voltages for?
Thanks Bob, I knew Vssa is the lowest you could get pretty much, I need the differential voltage to power an opamp. Do you think there's a way to stabilize the RS232 port output?
update: more info here thanks to google
Can't you use the PSoC5 opamps with a level-shifter to have their inputs between GND and VCC?
Two approaches -
1) Gen the negative supply with didode charge pump or external sw cap
chg pump reg.
2) Offset signals going into PSOC.
Attached some info on doing both.