Semiconductor Memory Predecode Line Repeater Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor memory devices, the large parasitic capacitance and wiring resistance due to miniaturization lead to significant delays in signal transmission, particularly affecting predecode lines, which hinder the speed of the memory device.
Innovation Solution
The integration of a repeater between the control circuit and the word line driver in the semiconductor memory device reduces the loading capacitance and fan-out of predecode lines by splitting the predecode line into two portions, one from the control circuit to the repeater and another from the repeater to the word line driver, utilizing CMOS inverters in series to manage signal levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the predecode line is extended to cover a large area in a semiconductor memory device, then the memory capacity is increased, but the signal delay increases due to wiring resistance and parasitic capacitance
Solution Approach 1:
The predecode line is divided into multiple segments with repeaters inserted at intermediate points. Each segment has its own driver, allowing the signal to be regenerated at each repeater location. This segmentation reduces the effective length of each wire segment, thereby reducing the cumulative wiring resistance and parasitic capacitance effect while maintaining the ability to cover large memory areas.
Solution Approach 2:
Repeaters are introduced as intermediary components along the predecode line. These repeaters act as intermediate signal regeneration points that receive the predecode signal from one segment and drive the next segment. The repeaters compensate for signal degradation caused by wiring resistance and parasitic capacitance, enabling extended predecode line coverage without proportional increase in signal delay.
2Area of stationary object
If the wiring width is reduced to miniaturize the semiconductor device, then the device area is reduced, but the wiring resistance increases
Solution Approach 1:
The predecode line is divided into multiple shorter segments with repeaters at intermediate points. By segmenting the long narrow wiring into shorter sections, the cumulative resistance effect is reduced even though each segment maintains the narrow width required for miniaturization. The repeaters compensate for the resistance in each segment, allowing the use of narrow wirings throughout the extended memory structure.
Solution Approach 2:
Repeaters are inserted as intermediary components that actively compensate for the high wiring resistance caused by narrow wire widths. Each repeater receives the signal after it has traversed a narrow wiring segment and regenerates it with sufficient strength to drive the next segment, effectively overcoming the resistance limitation imposed by miniaturized wiring dimensions.
3Speed
If repeaters are inserted to reduce signal delay, then the operation speed is increased, but the device complexity increases
Solution Approach 1:
The repeaters are designed with a standardized structure that performs multiple functions: signal regeneration, level restoration, and continued signal propagation. This multi-functionality reduces the need for separate specialized components and allows the same repeater design to be replicated throughout the extended predecode line, managing complexity through standardization while delivering speed improvements.
Data Source
AI summary
Along with the miniaturization of the semiconductor memory device, the resistor and parasitic capacitance of the wires become large, which prevents the semiconductor memory device from being speeded up. In a semiconductor memory device having a semiconductor substrate having a main surface, a first memory cell row having a plurality of first memory cells arranged in parallel to a first direction in plan view on the main surface, a first word line connected to the plurality of first memory cells, a first word line driver for changing a potential of the first word line, and a control circuit for outputting a first predecode signal to the first word line driver via the first predecode line in response to a clock signal and an address signal, a repeater is inserted between the control circuit and the first word line driver.