A Low-Area and Low-Power Comma Detection and Word Alignment Circuits for JESD204B/C Controller

Abstract

In an 8B/10B mode giga-bit-per-second serial data transactions, the de-serialized data is sent to a comma detection and word alignment (CDWA) module to identify the word boundaries, which is a prerequisite in the high-speed transceivers such as PCIe, USB and JESD204B/C. In order to ensure that the comma code (/K/-code) can be correctly detected. Ten 10-bit comma detector cells are adopted in a typical CDWA module, which require a complex circuitry and an enormous power consumption. To overcome these limitations, a low-area and low-power CDWA circuit for JESD204B/C transceiver chip in 8B/10B mode has been proposed in this paper. The bit width of the detector cells can be truncated from 10 to 6 under the condition, that CDWA module can detect a complete comma code correctly. On one hand, the proposed CDWA module is verified with a FPGA development platform with the reduction of the hardware resources and power consumption to 31.72% and 20.11% respectively as compared to the typical structure available. On the other hand, a 10-Gbps transceiver chip with the proposed CDWA module is fabricated with a 55-nm CMOS process and the word alignment function of the proposed module is proved by the measurement results. The area of this transceiver chip including 2× transmitting links and 2× receiving links is 2.89 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and the power consumption is 467.8 mW, under a maximum data transmission rate of 10 Gbps.