RPIXP2850BB Intel, RPIXP2850BB Datasheet - Page 35

• Manufacturer Part Number: RPIXP2850BB
• Manufacturer: Intel

Specifications of RPIXP2850BB

• Operating Supply Voltage (typ): 1.3/1.5/2.5/3.3V
• Operating Supply Voltage (max): 1.575/2.7/3.465V
• Operating Supply Voltage (min): 1.235/2.3/3.135V
• Mounting: Surface Mount
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Not Compliant

Table 12.
3.2
3.2.1
Hardware Design Guide
RDRAM Subsystem Implementation Options (Sheet 2 of 2)
Rambus* Channel Design
The following sections provide a high-level overview of Rambus* channel design. For complete
design and layout details please refer to the Rambus* design guidelines which can be found on the
Rambus* website at www.rambus.com.
RSL Trace Requirements and Recommendations
The following is a list of RSL (Rambus* Signaling Level) trace requirements and
recommendations for Rambus* designs:
Dual-channel RIMM*
(eight devices per channel)
Quad-channel RIMM*
(four devices per channel)
•
•
•
•
•
•
All signals must be length-matched (RSL and clock signals) from the IXP28XX network
processor to each RDRAM pin. Signals are then length-matched for RDRAM to RDRAM pin.
Lines should be matched to within 10 mils.
No length-match requirement is necessary from the last RDRAM pin to the termination island.
Length matching must compensate for controller package substrate routing. These lengths are
provided in
For impedance control, use the following guidelines:
Post layout simulations are strongly recommended to ensure proper signal integrity.
— Note that the flight time of the package is 154ps/in and is typically 180ps/in on a standard
— 34 Ω for a short channel and 28 Ω for a long channel.
— Trace widths for the desired impedance should be obtained from the manufacturer of the
— Device loading is compensated by narrowing (necking) the trace width in the vicinity of
— The recommended electrical pitch is:
— Fine tuning of signal lengths may be required to meet timing and signal integrity
FR4 PCB. Hence the trace lengths provided in
flight delay of the target PCB. An example of this is provided in
PCB as field solvers may not be accurate.
RDRAM.
15 mm - 18 mm for a 128-Mbyte RDRAM and
12 mm - 18 mm for a 256-Mbyte RDRAM
requirements.
Option
Section
3.7.
Using 256-
768 Mbytes
384 Mbytes
Mbyte part
Memory per NPU
768 Mbytes
Using 512-
Mbyte part
1.5 Gbytes
Section 3.7
• Vendors: Elpida*, Samsung*
• Vendor: Samsung*.
• Rambus* is working with vendors to
establish a standard.
IXP28XX Network Processor
must be adjusted to reflect the
Comments
Section
3.7.
RDRAM
35