TMS320F28075: ePWM as clock source

David Daggett

Part Number: TMS320F28075
Other Parts Discussed in Thread: MSP430FR5738, , C2000WARE

Customer is looking to replace the MSP430FR5738 with the TMS320F28075 (PZP Package).

"We want to use ePWM to provide clocks to three signals. We have an external AD7779 ADC that we’re hooked into via SPI and we want to provide a clock for the main ADC Clock (MCLK) and also to start conversions at a regular rate (START). They are currently not connected to an ePWM GPIO and I’m wondering if we can route ePWM to these pins (they are GPIO89 & GPIO90 by the way) via XBAR. This doesn't look possible, but please confirm."

over 5 years ago

0 David Daggett over 5 years ago

TI__Intellectual 895 points

Omit the first sentence above. The FR5738 was on a different design. Miscommunication.

0 Subrahmanya over 5 years ago in reply to David Daggett

TI__Mastermind 24095 points

Hi,

YOu could instead use ECAP in APWM mode. This can also be equivalent to the clock signal you plan to generate with PWM.
And the ECAP output are available via OutputXBAR - this would in turn address you pin requirement.
You can refer to below example in C2000Ware to configure eCAP in APWM mode.
C:\ti\c2000\C2000Ware_2_01_00_00\driverlib\f2807x\examples\cpu1\ecap
ecap_ex1_apwm

0 David Daggett over 5 years ago in reply to Subrahmanya

TI__Intellectual 895 points

So does this mean that you would configure ePWM, and then drive it into eCAP, and then send it to OutputXBAR, which would then send it to our GPIO?

0 Subrahmanya over 5 years ago in reply to David Daggett

TI__Mastermind 24095 points

Hi,

No. There is no need for ePWM. You could use eCAP to generate PWM output (APWM mode).

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TMS320F28075: ePWM as clock source