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USB Low-Full-High Speed Peripherals

YuCh_4287461
New Contributor

What modes are cy7c65215 jtag's output pins: Open-drain or push-pull? Are they configurable?

Also, should we have a pull-up resistor for TDO (jtag master's input pin)?

SCB1 pins:

TDO        // jtag master input pin

TDI          // jtag master output pin

TMS

TCK

TRST

Thanks,

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1 Solution
YatheeshD_36
Moderator
Moderator

Hello,

You can add a weak pull up of 50 KOhm on TDI, TMS and TRST pins, and a pull down on TCK of the jtag interface to which the CY7C65215 is connected .

Best Regards,

Yatheesh

View solution in original post

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5 Replies
YatheeshD_36
Moderator
Moderator

Hello,

The JTAG pins are strong pull down. SCB 1 of CY7C65215 can be configured as JTAG Master, Once SCB 1 is configured as JTAG the other interface in CY7C65215 cannot be used.

The JTAG pins are fixed and cannot be configured.

Pull up resistor is not needed for TD0.

Best Regards,

Yatheesh

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YuCh_4287461
New Contributor

Does cy7c65215 have built-in pulling resistors for those open-drain pins?

Should we have pulling resistors on PCB board? Please help check pulling directions below.

SCB1 pins:

TDO        // pulling is not needed

TDI          // pulling high

TMS        // pulling high

TCK         // pulling low

TRST       // pulling high

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YatheeshD_36
Moderator
Moderator

Hello,

The the output pins are strong pull down and not open drain. There is no need of pulling ups or pull downs on the PCB board, they can be connected directly.

please refer to the USB TO SERIAL / JTAG CONVERTER in "Super speed Explorer Kit Hardware Files" in this link for better understanding where CY7C65215 is used.

Best Regards,

Yatheesh

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YuCh_4287461
New Contributor

According to "ez-usb fx3/fx3s hardware design guidelines and schematic checklist", 8.2 jtag, there are pulling resistors on FX3.

We use cy7c65215 but do not use FX3. I think we need those pulling resistors on jtag signals.

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YatheeshD_36
Moderator
Moderator

Hello,

You can add a weak pull up of 50 KOhm on TDI, TMS and TRST pins, and a pull down on TCK of the jtag interface to which the CY7C65215 is connected .

Best Regards,

Yatheesh

View solution in original post

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