Hardware Design Guidelines—Intel®IXP43X Product Line of Network Processors

Table 28.

Supported DDRII 16-bit SDRAM Configurations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address Size

Leaf Select

Total

 

DDR SDRAM

 

DDR SDRAM

# of

 

 

 

 

Page

 

 

 

 

 

Memory

Technology

 

Arrangement

Banks

 

 

DDR_BA[1

 

Size

 

Row

Column

DDR_BA[0]

Size

 

 

 

 

]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

256 Mbit

 

16M x16

1

13

9

ADDR[24]

ADDR[23]

32MB

1KB

 

 

 

 

 

 

 

 

 

 

The DDR_RCOMP signal must be terminated through resistors specified in Figure 26. This allows the DDRII/I controller to make temperature and process adjustments.

7.2DDRII/DDRI RCOMP and Slew Resistances Pin Requirements

Figure 26 shows the requirements for the DDRII/DDRI RCOMP pin.

Figure 26. DDRII/DDRI RCOMP Pin External Resistor Requirements

DDRI

 

R1 =387Ω ±1% resistor

 

OR

 

DDRII

 

R 1 = 285Ω ±1 % resistor

 

DDRIMPCRES

 

R1

Intel® IXP43X

DDRCRES0

Product Line of

 

Network Processors

R2

 

DDRSLWCRES

 

DDRI

 

R2 =845Ω ±1% resistor

 

OR

 

DDRII

 

R 2 = 825Ω ±1 % resistor

 

For example, when DDRI SDRAM is used, DDRIMPCRES is connected with 387Ω and DDRSLWCRES is connected with 845Ω resistor to DDRCRES0.

 

Intel® IXP43X Product Line of Network Processors

April 2007

HDG

Document Number: 316844; Revision: 001US

75

Page 75
Image 75
Intel IXP43X manual DDRII/DDRI Rcomp and Slew Resistances Pin Requirements, Supported Ddrii 16-bit Sdram Configurations