TL16C754C: Impact of replacing a TL16C754B with the TL16CP754C in a production design

Bryan Deguire

Part Number: TL16C754C
Other Parts Discussed in Thread: TL16C754B,

I want to replace a TL16C754B on a design that is in production with the TL16CP754C during a PCB respin for other reasons. The "C" data sheets states that it is "pin to pin" compatible but three pins have been removed. My concern is focused on determining what needs to be done in the absence of the INTSEL pin, it's being pulled high in the current design.

Thanks, Bryan

over 2 years ago

0 Tyler Townsend over 2 years ago

TI__Mastermind 47328 points

Hi Bryan,

This looks like a mistake in our datasheet saying TL16C754C is p2p with TL16C754B. There is clearly a mistmatch in the total number of pins between devices, although the 16C754 series of devices are both functionally capable UART devices and achieve nearly the same solution for UART applicatinos.

What pin on the "C" version is INTSEL connected to?

Regards,

Tyler

0 Bryan Deguire over 2 years ago

Prodigy 60 points

Hi Tyler,

I don't understand your question, the "C" version does not have a INTSEL pin.

0 Bryan Deguire over 2 years ago in reply to Bryan Deguire

Prodigy 60 points

Without the INSEL pin in the "C" version, does setting the MCR(3) pin high provide the same functionality as the "B" version with INTSEL pulled high?

0 Tyler Townsend over 2 years ago in reply to Bryan Deguire

TI__Mastermind 47328 points

Hi Bryan,

Let me get a response to you by noon CST tomorrow.

Regards,

Tyler

0 Tyler Townsend over 2 years ago in reply to Bryan Deguire

TI__Mastermind 47328 points

Hi Bryan,

I understand your question now.

TL16C754B uses both the INTSEL pin and the MCR register to continuously enable the interrupt output pins. The INTSEL pin can be used to override the contents of the MCR[3] bit selection. If INTSEL pin is enabled, then the functionality of the interrupts can be control via register reads to MCR[3] via software instead of hardware external input.

TL16C754C does not have an INTSEL pin, so the MCR register is the only way to continuously enable the interrupt pins.

Regards,

Tyler

0 Bryan Deguire over 2 years ago in reply to Tyler Townsend

Prodigy 60 points

Hi Tyler,

Could you determine if writing a "1" to MCR(3) in the "C" version provides the same operation as setting the INTSEL pin high in the "B" version?

Thanks, Bryan

+1 Tyler Townsend over 2 years ago in reply to Bryan Deguire

TI__Mastermind 47328 points

Hi Bryan,

Driving INTSEL = H on the "B" version forces continuous interrupts.

Only the MCR register can control the continuous function of the interrupts on the "C" version. Therefore, setting MCR[3] = 1 will set the interrupts to the active (continuous) state the same way as the "C" version.

Regards,

Tyler

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TL16C754C: Impact of replacing a TL16C754B with the TL16CP754C in a production design