JTAG Connectivity!

[qammarabbas]

Hi,

I am using a COP connector as JTAG header connected to T1042. I found a reference schematic in which there is a 1.8 - 3.3V bidirectional converter between the header and processor. However, when i studied the datasheet of T1042, it did not show any converter. Can someone please tell me the reason?

Please find the attached image for your information. Thank you!

[r8070z]

Have a great day,

The datasheet specifies that the T1040 JTAG/COP signal buffers powered by OVDD=1.8V+/- 0.09V and the maximal input voltage on it must not exceed OVDD by more than 0.3V. Correspondingly the output signals are less than OVDD. While on the reference board JTAG/COP connector expects 3.3V interface signals from the debugger - you can see connector’s pin 6 (COP_VDD_SENSE) is connected to the 3.3V. Due to that they add a 1.8 - 3.3V bidirectional converter between the header and processors.

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