Multiplexing adaptive synchronization circuit for pins of system-on-chip

Abstract

A multiplexing adaptive synchronization circuit for pins of a system-on-chip comprises an automatic test device and a clock module, the automatic test device is connected to a to-be-tested chip MCU bya single bus, and an edge acquisition circuit and an adaptive synchronization circuit are arranged in the to-be-tested chip MCU. The edge acquisition circuit is used for receiving START start pulsestransmitted by the automatic test device, detecting and determining the pulse width and the baud rate of the pulses, and transmitting the pulses to the adaptive synchronous circuit. The adaptive synchronous circuit receives the pulse width transmitted by the sampling edge circuit and determines a sampling interval of a subsequent bus; according to the invention, the use of an external clock and acorresponding PAD pin is avoided, the communication between test equipment or an upper computer and the to-be-tested MCU chip can be ensured under the condition of no calibration, and when the circuitis used for the digital-analog hybrid chip, the to-be-tested chip is prevented from being damaged by the MCU of the to-be-tested chip. Communication faults caused by clock precision deviation can beavoided.

Description

Technical field: [0001] The invention relates to the technical field of chip design, in particular to a system-on-chip pin multiplexing adaptive synchronization circuit. Background technique: [0002] Micro control unit MCU, also known as single-chip microcomputer or single-chip microcomputer, is to appropriately reduce the frequency and specifications of the central processing unit CPU, and integrate memory (memory), counter (Timer), USB, A / D conversion, UART, PLC , DMA and other peripheral interfaces, and even LCD drive circuits are integrated on a single chip to form a chip-level computer, which can be used for different combination controls for different applications. The central processing unit (CPU) in the microcomputer is called the microprocessor (MPU), which is the core component of the microcomputer, and it can also be said to be the heart of the microcomputer. It plays the role of controlling the work of the entire microcomputer, generates control signals to cont...

AI Technical Summary

Problems solved by technology

For power chips with MCU core digital-analog hybrid, the pin resources are scarce, and different test modes can only be selected in sequence through individual pins. Since the chip clock circuit has not been calibrated at this time, a certain fixed baud rate will appear. The communication failure of some chips makes it difficult for some chips to enter the corresponding test mode, and it is necessary to provide a stable clock by means of an external clock or an external power supply.

lead to increased testing costs

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