JAJSQ97J may 2009 – january 2021 XIO2001
PRODUCTION DATA
In the bridge, the PCI bus I/O drivers are powered from the VDD_33 power rail. Plus, the I/O driver cell is tolerant to input signals with 5-V peak-to-peak amplitudes.
For PCI bus interfaces operating at 50 MHz or 66 MHz, all devices are required to output only 3.3-V peak-to-peak signal amplitudes. For PCI bus interfaces operating at 25-MHz or 33-MHz, devices may output either 3.3-V or 5-V peak-to-peak signal amplitudes. The bridge accommodates both signal amplitudes.
Each PCI bus I/O driver cell has a clamping diode connected to the internal VCCP voltage rail that protects the cell from excessive input voltage. The internal VCCP rail is connected to two PCIR terminals. If the PCI signaling is 3.3-V, then PCIR terminals are connected to a 3.3-V power supply via a 1-kΩ resistor. If the PCI signaling is 5-V, then the PCIR terminals are connected to a 5-V power supply via a 1kΩ resistor.
The PCI bus signals attached to the VCCP clamping voltage are identified as follows