Hi Sue,
With regard to your questions:
SCLK0 - This is the clock that the SMC uses to clock its logic and to count delays.
CLKOUT - In the SMC chapter this means that CGU_CLKOUTSEL.CLKOUTSEL has been set to SCLK0, which provides the pad-delayed version of SCLK0.
SCLK - Since the SMC is used on more than one part the HRM refers to the clock it uses as SCLK. In the case of BF60x parts the SMC SCLK is SCLK0. This is specified in the data sheet and other places in the HRM.
This sentence "All memory control, address and data signals are driven out of chip with regard to the falling edge of the CLKOUT signal, except for burst clock." refers to the fact that most timing could be computed based on CLKOUT (programmed to SCLK0), though in AC timing specs the data sheet doesn't do so since it is not directly part of the SMC interface and it is meant to be an asynchronous peripheral in most modes. This enables easier computation for customers who aren't connecting CLKOUT to their SMC-controlled device. In the case of synchronous burst mode the burst clock is used as a clock reference.
Does that help clear things up?
Regards,
Joe