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CB35000 SERIES

®

LIBRARY OVERVIEW

The design of the CB35000 family has been

optimized to allow extremely high density, high

speed and low power designs. For these reasons

a wide range of cells with different ranges of

driving capability are available in the library.

The library cells have been optimized in term of

functional and electrical parameters in order to

have:

s

Good balancing

s

Maximum speed

s

Optimum Threshold voltage

s

Symmetric Vdd/Vss Noise margin

s

Minimum Power-Speed figure

Surrounding

the

core

are

configurational

specialized transistors forming a Sea of I/O giving

a high degree of flexibility to the system designer.

The

geometrical

aspect

of

the

cells

was

configured to allow extremely dense design, fully

10 Êm

Figure 2. ND2 Core Cell

exploiting the features of the Place and Route

tool in terms of horizontal and vertical routing

grids. For Place and Route, three levels of metal

are utilized. Intracell and intercell wiring are

limited to first metal, with second and third metal

levels dedicated to interconnect wiring and power

distribution. Each cell gives the possibility to use

10 horizontal wiring channels using third metal.

With the horizontal grid unit being the same as

the Metal 2 minimum contacted pitch, the vertical

wiring can be done on every grid point, without

limitation.

TECHNOLOGY OVERVIEW

A major feature of the HCMOS5S process is

salicided active areas. This results in source

drain areas that are of one to two ohms

resistance as opposed to the hundreds or

thousands of ohms of source drain resistance in

previous technologies. This very low resistance is

one reason that very low transistor widths could

be utilized in the cell design since drive is not lost

due to source drain resistance. This use of low

width transistors results in lower capacitance

loading of the gates due to the smaller areas

utilized. Low resistance, low capacitance, and

small gates results in low power usage for

inverters as compared to previous technologies.

The reduction in power consumption allows the

usage of salicided active stripes to distribute

power internally to the simple cell, replacing, in

some cases, the usage of the first metal layer.

This saves silicon area by allowing greater

density, permeability and routability of the cells

resulting in greater overall circuit density.

The standard power distributions are Internal Vdd

and Vss, serving the internal cells and the

prebuffer sections of the I/O, External Vdd and

Vss serving the output transistors only, and

Receiver Vdd and Vss serving the first stages of

the receiver cells. Optional distributions for 5.0V

interface, GTL, CTL, and other standards can be

utilized as necessary.