Minium Mclock for USB operation

[paulbrown9]

Posted on November 29, 2004 at 08:02

Minium Mclock for USB operation

[paulbrown9]

Posted on November 25, 2004 at 13:32

I have a 4MHZ clock for the main CK input and HCLK input. I use PLL2 to generate 48MHZ for USB operation. If I set the RCLK and MCLK to 16MHZ the sample mouse demo works, If I set the MCLK to 12MHZ then USB connection is not established. Is this correct and is there a minumum mclk/rclk speed required for USB to operate.

P.

[smartpocket]

Posted on November 26, 2004 at 04:09

Hi ReservoirGerbils,

Have you setting the APB1 clk > 8MHz ? This is a must for USB funcionality . . .

If you set the RCLK and MCLK to 12 MHZ the work frequency of APB1 is 6MHz !!! (-->> USB NOT RUN)

Smart

:p

[paulbrown9]

Posted on November 29, 2004 at 08:02

Thankyou for this

I have now located the reference to this is the reference manual i suppose I should do more reading ;-).