TMS320C5545: RTC clock to extrenal device

amit davidosn

Part Number: TMS320C5545

Hi, we have used tms320c5505 in other designs and we have the option to use the RTC clock 32.768KHz to drive external unit via RTC_CLKOUT pin (D8).

Now we are going to use tms320c5545 for new design and do not see this option. Would this mean we cannot take the clock out to another device? or there is another way?

Thanks

over 6 years ago

0 Cvetolin Shulev-XID over 6 years ago

TI__Guru 65405 points

Hi Amit,

TMS320C5545 has CLKOUT pin (C12). Please refer to Datasheet Figure 4-1:

Check also section 6.8.3. and Note:The bootloader disables the CLKOUT pin through CLKOFF bit in the ST3_55CPU register. You should additionally enable CLKOUT pin if you want to use it.

Regards,

Tsvetolin Shulev

0 amit davidosn over 6 years ago in reply to Cvetolin Shulev-XID

Prodigy 205 points

Hi, C12 - is the DSP PLL clock out. I was referring to RTC clock. The 32.768KHz clock crystal that we use. in C5505 we have RTC_CLKOUT pin (D8) which takes out the 32KHz and we can use it for our needs.....do we have the same option with C12 pin? which is the DSP clock?

Thanks

0 Cvetolin Shulev-XID over 6 years ago in reply to amit davidosn

TI__Guru 65405 points

TMS320C5545 CLKOUT pin (C12) is not equivalent to C5505 RTC_CLKOUT pin (D8). CLKOUT pin output is programmable and you can select a clock source as it is described in TRM section 1.4.2.3:

It is recommended to be used for debug purpose.

Regards,

Tsvetolin Shulev

0 amit davidosn over 6 years ago in reply to Cvetolin Shulev-XID

Prodigy 205 points

Ok, thanks

In our older design, using 5505/4 D8 pin, we used to drive a FM radio using the clock 32.768KHz. It works very well in our design. In the 5545 we can configure the clock to this freq specific? we know it is for debug and we take responsibility.

Thanks

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TMS320C5545: RTC clock to extrenal device