HP Workstation x2000 hp workstation x2000 - Technical Reference and Troublesho - Page 71

System Board System Bus Figure 2-14 System Bus The system bus of the Pentium IV processor is implemented in the Gunning Transceiver Logic (GTL)+ technology. This technology features open-drain signal drivers that are pulled up through resistors at bus extremities to the operating voltage of the processor core. These resistors also act as bus terminators and are integrated in the processor and in the 82850 MCH. The System Bus Socket 423 Intel Pentium IV Processor Address (32) Control Data (64) 1.5V AGP Pro Connector AGP 4x Bus (133MHz (1GB/sec data transfer rate) 100MHz two-way system bus (data bus runs at 4 x 100MHz, 3.2GB/s transfer rate) 850 Memory Dual Rambus channel 4 onboard RIMM Controller Hub (MCH) 82850 3.2GB/s at 400MHz data transfer rate) sockets supporting RDRAM memory HUB LINK 8 (266MB/s data transfer rate) I/O Controller Hub The supported operating frequency of the GTL+ bus for the Pentium IV is 100MHz. The width of the data bus is 64 bits, whereas the width of the address is 32 bits. Data bus transfers occur at four times the system bus, at 400MHz. Along with the operating frequencies, the processor voltage is set automatically. The control signals of the system bus allow the implementation of a "split -transaction" bus protocol. This allows the Pentium IV processor to send Chapter 2 71