You can find information about SWV in PSoC 3 Tehnical Reference Manual. Unfortunately, the support for SWV is not yet available in current version of PSoC Creator.
SWV supported in MicroVision and Red Suite, which will be supported by the end of 2011.
Here is some general info on the SWV in PSOC
Thirty-two 32-bit data mailboxes
Instruction trace also supported in PSoC 5
only support equivalent of ARM ITM on PSoC 3
may be used alone or simultaneously with SWD
not compatible with JTAG
1 wire using UART of Manchester encoding
up to 33 MHz rate.
Is there a standard function to call in C to send printf like debug messages?
I was not able to find anything related to SWV and MicroVision on Google. It displays this thread as the first entrance. Can provide some links to MicroVision and Red Suite.
Thanks for the suggestion to check TRM.