I had posted the question to philips and their answer is appended below.

Philips Semiconductors answer:
Unfortunately, our comparisson table was in error. The clock mode can
be changed from it's default 12 clock mode to 6 clock mode via ISP or
IAP. However, once it has been put in the 6 clock mode, it requires a
parallel programmer to put it back in 6 clock mode.

Jim E.

Thanks for all the responses.