Circuit for configuring chip pins with multiplexing functions, and method for configuring chip pins with multiplexing functions

Abstract

The configuration circuit includes circuit of LED indicator light, bypass resistor, alternation switch. The alternation switch includes two pieces of LED drive pins, control pin for setting up í«0í», control pin for setting up í«1í», grounding pin, and pin for setting up voltage. The circuit of LED indicator light is connected to LED drive pins of the alternation switch. Control pin for setting up í«0í» and control pin for setting up í«1í» are connected to same functional multiplexing pin A of a chip. Bypass resistor is connected to circuit of LED indicator light in parallel. If pin A is needed to be configured as í«0í», through the control alternation switch, LED drive pin and control pin for setting up í«0í» are connected to grounding pin. If pin A is needed to be configured as í«0í», through the control alternation switch, LED drive pin and control pin for setting up í«0í» are connected to pin for setting up voltage. The circuit is simple and reliable.

Description

technical field [0001] The invention relates to a configuration circuit, in particular to a flexible configuration circuit and a method for configuring function multiplexing chip pins in an Ethernet chip for communication. Background technique [0002] In the current Ethernet chips, the working mode of some chips can be configured through specific pins. In order to save costs in chip design, the configuration pins are often multiplexed with other pins. Foot reuse. At the initial stage of chip power-on, the pins play a configuration role, and after a period of stable power-on (generally about tens of milliseconds), the pins are used to drive the indicator light. The indicator lights generally use light-emitting diodes, and the driving mode of the indicator lights must be consistent with the power-on configuration of the pins. [0003] The working principle of the chip pin that multiplexes the two functions of default configuration and LED driving is as follows (assuming tha...

AI Technical Summary

Problems solved by technology

[0010] 1. Inconvenient hardware design

Since the chip pins are fixed to "0" or "1", once the printed circuit board (PCB) is placed on the board, it cannot be changed, resulting in a certain default state inside the chip that cannot be changed by hardware after power-on.

At this time, if the configuration is wrong, or the default configuration state of the chip needs to be re-modified, it is necessary to temporarily change the hardware circuit, which is very inconvenient

[0011] 2. Poor circuit reliability

use figure 1 or figure 2 The design method, if the LED indicator is damaged, the configuration circuit will fail, and the chip cannot be reliably configured for its working mode when it is powered on

Images