This is a user guide for XIO2000A EVM, which includes product instructions, features and characteristics
The XIO2000A Evaluation Board (EVM) implements a PCI Express to PCI bridge using the Texas Instruments XIO2000A chip. It is a half‑width PCI Express add‑in card with a standard 4‑layer board (2 signals, 1 power, 1 ground) and 100‑Ω differential impedance.
The manual covers EVM features such as PCI Express connector, three PCI add‑in slots, EEPROM interface, test header, CLKRUN power‑saving signal, LED status indicators, a bill of materials and full schematics, plus a troubleshooting section that walks users through power checks, bridge configuration and downstream device verification.
| Board layers | 4‑layer (2 signals, 1 power, 1 ground) |
|---|---|
| Differential impedance | 100 Ω differential (50 Ω single‑ended) |
| Power rails supplied | 3.3 V and 12 V from PCI Express connector |
| Derived voltages | 1.5 V, 5 V and –12 V generated on‑board |
| PCI add‑in slots | Three standard PCI slots (5 V VIO clamping) |
| Maximum PCI bus speed | 66 MHz when compatible cards are installed |
| CLKRUN default state | Disabled by default |
| LED indicators | D1 5‑V, D3 3.3‑V, D4 12‑V, D5 PERST, D6 WAKE, D7 PCI‑EM |
Verify the EVM power, confirm the bridge is link‑training, ensure the bridge has been configured, and check downstream devices.
The board detects the lower‑speed device and automatically sets the bus speed to 33 MHz.
Populate resistor R24 with a 10 kΩ 0805 resistor; this enables CLKRUN and maps GPIO1 to the CLKRUN signal.