I am not aware of any way of implementing TCP/IP in PSoC 5 natively. I am not aware of any TCP/IP Stack having been ported to PSoC 5 either.
I have, however, successfully integrated TCP/IP, UDP and a web browser into PSoC 5 products by using external devices.
As far as I am aware the PSoC 5 does not have a MAC or a PHY, both of which are physically required to implement ethernet.
My soultion was to use a PIC18F67J60, which has both MAC and PHY and runs the free microchip TCP/IP stack and connect it to the PSoC using I2C. This means that there is no need to develope your own TCP/IP Stack and it frees the PSoC core for doing other tasks. You will need to add a PHY and MAC anyway, so this method does not increase the component count. The only other components required are an RJ45 Jack with built-in magnetics, a 25 Mhz crystal or oscillator and a few passive components.
There are other ways to implement ethernet - you could just choose your own MAC and PHY chip(s) and code your own stack - but it is a big task. I don't think there is any need to re-invent the wheel.
You mat want to consider a very fast and reliable Ubicom IP2022 Network Processor made by Qualcomm (Ubicom was purchased).
Last stable tool attached as exe use the Jtag debugger, you need to make a simple parallel port Jtag adapter a few wires.