Understanding Daisy Chaining: Definition, Advantages, and Switches

Daisy chaining is a method of connecting multiple devices in a sequence, one after the other. Think of it like a series circuit. This article dives into the fundamentals of daisy chaining, its advantages, and how it relates to switches.

The process in which devices are interconnected in series one after the other is known as daisy chaining. It is equivalent to series circuit. As we are aware that many of the SPI devices can not be addressable individually. They need separate extra hardware in order to be interfaced with single device on bus. This hardware complexity is avoided in daisy chain architecture. This is shown in the figure-1.

Here commands issued from microcontroller propagates from one slave device to the other. Here DOUT of first device is connected with DIN of the next device and so on.

Figure-2 depicts daisy chaining execution cycle diagram. Hence during active low of CS, commands are loaded into register of 3 devices one by one during 3 clock SCLKs. Each SCLK consists of 16 cycles. Once the commands are loaded they can be executed by making CS signal to HIGH state.

Advantages of Daisy Chaining

Here’s why daisy chaining can be a beneficial approach:

• Simplified Hardware: Designing for multiple slave devices controlled by a single master becomes less complex. Less extra hardware is needed.
• Easy Operation: Selecting slave devices and executing commands is simplified through software programming.
• Scalability: It’s easy to add more nodes or devices to the chain, up to the limits defined by the interface bus standard you’re using. For example, SCSI-2 supports up to 16 devices/nodes.

Daisy Chaining Switches

Daisy chaining isn’t limited to just SPI devices. Technologies like Thunderbolt also support it. The latest Thunderbolt technology based devices support daisy chaining. Refer Thunderbolt1,2,3 for more information. Even Ethernet switches can be daisy-chained. Switches designed for this purpose are called “daisy chain switches.”

When shopping for Ethernet switches, be sure to check if they support daisy chaining if that’s a feature you need.