TUSB1210: need a solution to interface it with 3.3V Microcontroller

Sagar Kumar18

Part Number: TUSB1210

Hi,

I am using TUSB1210BRHBR in my design and have some doubts regarding level translator. I used SN74AVC8T245DGVR for all 8 data signals and DIR pin of this translator connect to TUSB1210 DIR O/P pin. My doubt is how ULPI DIR pins tell when Data will be tranfer from MCU to ULPI or UPLI to MCU.

Second Issue is after that we are haiving STP. RESET CS signals which i/p to ULPI and NXT and CLOCK O/P from ULPI how to convert these signals. Can i use TXB0106PWR and make its OE pin remain pull up? And how to control DATA signals level translator SN74AVC8T245DGVR 's OE pins since it is active low and in datasheet they mention it should be tied to VCC for proper power up. its means i have to provide 1.8V control signal from MCU.

over 5 years ago

0 Brian Zhou over 5 years ago

TI__Guru*** 146285 points

when PHY has data to transfer to link , it drive DIR to high to drive the bus. When PHY has no data to drive, it drive DIR to low to monitor bus for link activity.

why don't you just use bi-directional level shifter for data signal as well?

0 Sagar Kumar18 over 5 years ago in reply to Brian Zhou

Prodigy 180 points

Yes I can use. then what is the use of DIR ?

0 Brian Zhou over 5 years ago in reply to Sagar Kumar18

TI__Guru*** 146285 points

DIR is needed by ULPI itself.

0 Sagar Kumar18 over 5 years ago in reply to Brian Zhou

Prodigy 180 points

How is it needed by itself since it is a o/p pin?

0 Brian Zhou over 5 years ago in reply to Sagar Kumar18

TI__Guru*** 146285 points

May be I misunderstood your question. DIR is controlled by PHY ULPI , you don't need to control it.

0 Sagar Kumar18 over 5 years ago in reply to Brian Zhou

Prodigy 180 points

So I have two options-

1. Use one bidirectional level translator and it DIR pin controlled by ULPI DIR pin. and other control pins(STP, NXT, RESET, CS) can be use by other 4 bit level translator where we ca define direction for each and every 4 pins.

2. Use two 8 bit level translator(one for data bits and other1 for control pins) which does not have any DIR pin, only have OE enable pins and we control this OE pin with MCU using any open drain buffer.

Let me know which option is best to go in design

0 Brian Zhou over 5 years ago in reply to Sagar Kumar18

TI__Guru*** 146285 points

option 2 is better and OE is always on.

0 Sagar Kumar18 over 5 years ago in reply to Brian Zhou

Prodigy 180 points

Can i control OE through MCU with open drain buffer? So that MCU also has control over it.

0 Brian Zhou over 5 years ago in reply to Sagar Kumar18

TI__Guru*** 146285 points

sure, it should work

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TUSB1210: need a solution to interface it with 3.3V Microcontroller