ADC clock

Hi 

I have a doubt on ADC clock for 28069 controller.

I am using TMS320f28069 controller and I am operating at 90MHZ.  from the data sheet I found this:

CLKDIV2EN      CLKDIV4EN      ADCCLK

        0                         0                SYSCLK
        0                         1                SYSCLK
        1                         0                SYSCLK / 2
        1                         1                SYSCLK / 4

My doubt are : 

1. Can I use ADC clock same as SYSCLK(90MHZ)?

2. If I configure adc as : AdcRegs.ADCCTL2.bit.CLKDIV2EN = 1; My adc clock will be 45MHZ.Does the adc work with this clock(45MHZ)?

3. Is there any minimum and maximum adc clock limit(for TMS320f28069)?

Thank You

Githin