7 series High Range (HR) Select I/O banks have a VCCO power sequencing requirement. This requirement applies to Artix-7, Kintex-7, Virtex-7, and Zynq-7000 (both PS and SelectIO) devices. All devices have at least one High Range bank; the Configuration Bank 0 for all silicon revisions (ESLAB, Initial ES, General ES, Production).
According to the specification, "for VCCO voltages of 3.3V in HR I/O banks and configuration bank 0, the voltage difference between VCCO and VCCAUX must not exceed 2.625V for longer than TVCCO2VCCAUX for each power-on/off cycle to maintain device reliability levels."
If in a hot-swap situation, an unpowered device is subject to a Vin greater than 2.625V (assuming Vccaux is unpowered i.e.,0V), then the specification quoted above is violated.
It is also important to note that clamp diodes are always present on the I/O. So, when driving a potentially unpowered bank, there will be current forward biasing the clamp diodes. The Iin specification from the data sheet needs to be observed to ensure current on both an I/O and Bank basis are within specification.
The behavior of the I/O is not guaranteed until the device is powered up.
| Answer Number | 问答标题 | 问题版本 | 已解决问题的版本 |
|---|---|---|---|
| 51834 | SelectIO Design Assistant - Reliability and over driving IOs. | N/A | N/A |
| 37347 | 7 Series FPGAs - Will driving the I/Os of an unpowered bank cause damage to the part? Do 7 Series devices support hot swap? | N/A | N/A |