Nortel Networks Circuit Card User Manual

 NT4N39AA CP Pentium IV Card

double pumped address bus (addresses running at 2*100 MHz = 200 MHz) is 
32 bit wide supporting an address range of up to 4 GBytes. The processor 
voltage specification is compliant with IMVP IV specification.

CP PIV memory uses DDR SDRAM technology. The CP PIV provides a 
maximum of two GBytes using two vertical DIMM sockets to install 
off-the-shelf DIMM modules. CP PIV only supports DDR SDRAM DIMM 
memory with a supply voltage of +2.5V.

The memory data path is 72-bit wide. The Intel 855GME Host Bridge 
supports 128 MByte, 256 MByte and 512 Mbyte SDRAM technologies with 
a maximum ROW page size of 16 Kbytes and CAS latency of 2 or 2.5. The 
maximum height of the DIMM modules possible on CP PIV is one inch or 
25.4 mm.

The DDR interface runs at 100 MHz synchronously to the front side bus 
frequency. The SPD (Serial Presents Detect) -SROM available on DIMM 
modules provide all necessary information (speed, size, and type) to the 
boot-up software. The SPD-SROM can be read via SMBUS connected to the 
Intel Hance Rapids South Bridge. 

The physical interface for the COM1 and COM2 ports to the front panel is 
through a stacked dual Male DB9 Connector. The corresponding pin details 
are shown in Table 72.

DCD

RXD

TXD