Personal tools
You are here: Home Forums SH Family Maximum Input Clock Restriction

Maximum Input Clock Restriction

Up to SH Family

Maximum Input Clock Restriction

Posted by su shin jah at June 10. 2008

Understand from the user manual that for TCLKA: 

The input clock pulse width must be at least 1.5 states in the case of single-edge detection, and at

least 2.5 states in the case of both-edge detection. The MTU2 will not operate properly at narrower

pulse widths.

So if my clock is run at 160Mhz, and I am using single-edge detection, so the maximum clock input for TCLKA = 160/1.5= 106.67Mhz ? Anybody can help on this? Thanks.

Re: Maximum Input Clock Restriction

Posted by FrankL at June 10. 2008

This 1.5 cycles is 1.5 cycles of the peripheral clock, NOT of internal clock. If the max. peripheral clock is 40MHz, TCLKA input is max 26.6MHz

Re: Maximum Input Clock Restriction

Posted by su shin jah at June 11. 2008

Thanks for reply.

So even though I use the 160MHz crystal for the CPU main clock source, the TCLKA input max still 26.6Mhz(since the peripheral clock is 40Mhz)?

Re: Maximum Input Clock Restriction

Posted by FrankL at June 12. 2008

Correct.

Re: Maximum Input Clock Restriction

Posted by su shin jah at June 17. 2008

I am doing a sampling signal from video which has frequecy at 28Mhz. So in order to capture it fully without losses, can I still use TCLK1 as it max input is only 26.67Mhz?

Btw do you have any video sampling application by using SH7211?

Powered by Ploneboard