JTAG and SPI Protocol

Name: JTAG and SPI Protocol
Rating: 4.4 (26 reviews)

Created byPySolve Semiconductors

Last updated 3/2025

English

English [Auto],

What you'll learn

Definition of JTAG (Joint Test Action Group).
Purpose of JTAG in hardware testing and debugging.
Typical use cases, including testing PCBs and programming FPGAs.
Concept of boundary scan technology.
How boundary scan enables testing without physical probes.
The role of boundary scan in detecting manufacturing defects.
Explanation of the TAP controller.
Functions of each TAP pin (TDI, TDO, TCK, TMS, TRST).
How TAP facilitates communication with boundary scan cells.
Structure and operation of boundary scan cells.
How they interface with device I/O and internal logic.
Using boundary scan cells for observing and controlling pin states.
What SPI is and where it is used.
Key features of SPI: full-duplex communication, simplicity, and high speed.
Typical applications in embedded systems and peripheral communication.
The roles of Master and Slave devices in SPI.
How the Master generates the clock and initiates communication.
How Slave devices respond to the Master.
Detailed explanation of how data is transmitted via MOSI and MISO lines.
The function of SCLK (Serial Clock) and SS (Slave select) lines.
The bidirectional data flow in full-duplex mode.
Explanation of CPOL and CPHA settings.
How these settings affect data sampling and data shifting.
Importance of matching clock settings between Master and Slave.
SPI Mode 0 (CPOL = 0, CPHA = 0): Data is sampled on the rising edge of the clock.
SPI Mode 1 (CPOL = 0, CPHA = 1): Data is sampled on the falling edge of the clock.
SPI Mode 2 (CPOL = 1, CPHA = 0): Data is sampled on the falling edge, with an idle high clock.
SPI Mode 3 (CPOL = 1, CPHA = 1): Data is sampled on the rising edge, with an idle high clock.
How to connect multiple Slave devices to a single Master.
How the SS line is used to select different Slave devices.
Considerations for wiring and communication management.
Explanation of the daisy-chain configuration.
How data is passed through multiple Slave devices in a series.
Advantages and limitations of the daisy-chain approach.

Course content

2 sections • 14 lectures • 1h 23m total length

What is JTAG3:54
JTAG provides a standard way to test and verify integrated circuits without physical access, enabling debugging, programming, and security applications in modern electronics.
Boundary Scan Overview14:56
Explore boundary scan architecture to enable efficient IC testing via scan chains, a test access port, and instruction and data registers, including boundary scan, bypass, and device ID registers.
Test Access Port (TAP)5:58
Explore the JTAG test access port (tap) and its signals—tde, tdo, tc, tms, and tr t—and how data shifts through a chain for debugging and fault isolation.
Boundary Scan Cells8:05
Explore how boundary scan cells use pi and P0, capture and update hold cells, and manage scan in and scan out via the mode signal under normal and test operation.

Introduction8:40
Learn the serial peripheral interface (spi), a synchronous, full‑duplex master‑slave protocol using mosi, miso, clk, and ss for high-speed communication with sensors and multiplexers.
Master and Slave5:27
Master generates the clock to synchronize data transfer with slaves on the spi bus, while chip select enables one slave (usually active low) and Mosi and Miso handle data flow.
SPI Communication4:37
Learn how the master initiates spi communication by sending the clock signal and asserting chip select, enabling full duplex data transfer over mosi and miso with synchronized clocking.
Clock Polarity and Clock Phase4:44
Configure SPI using Cpol and CPR to select four modes, defining idle clock level and whether data is sampled on the first edge and shifted out on the next.
SPI Mode 0 (CPOL = 0, CPHA = 0)3:59
Explore spi mode zero: clock idle low, data sampled on the rising edge and shifted on the falling edge, with cs, clk, mosi, and miso exchanging msb-first 0x3c and 0x87.
SPI Mode 1 (CPOL = 0, CPHA = 1)3:19
Explore SPI mode one (CPOL 0, CPHA 1) showing data sampled on the falling edge and shifted out on the rising edge, with MOSI and MISO exchanging in full duplex.
SPI Mode 2 (CPOL = 1, CPHA = 0)2:53
Illustrate spi mode two (cpol=1, cpha=0) with example: clock idles high, data sampled on the falling edge, shifted out on the rising edge, via Mossi and miso lines with cs.
SPI Mode 3 (CPOL = 1, CPHA = 1)3:30
Explain spi mode three (cpol=1, cpha=1) with an example showing data sampling on the rising clock edge and shifting out on the falling edge, plus cs, mosi, and miso signaling.
Multi-slave Regular Configuration4:06
Master communicates with multiple slaves in regular mode, each slave with its own chip select line. Shared clock, MOSI, and MISO lines connect all slaves while CS lines prevent interference.
Multi-Slave Daisy-Chain Configuration in SPI9:15
Explore the SPI daisy chain method to connect multiple slaves to a single master using one chip select, with serial clock, data propagation via mosi and miso, and latency considerations.

Requirements

The only requirement is a willingness to learn. This course is designed for beginners and is open to anyone interested in learning about hardware communication protocols, regardless of their prior knowledge or experience.

Description

This course offers a comprehensive introduction to both JTAG (Joint Test Action Group) and SPI (Serial Peripheral Interface) protocols. It is designed for beginners with no prerequisites other than a willingness to learn. Students will gain a solid understanding of the fundamentals, practical applications, and theoretical knowledge of these essential hardware communication protocols. The course covers JTAG concepts such as boundary scan, Test Access Port (TAP), and boundary scan cells, alongside SPI topics including communication modes, master-slave configurations, clock polarity and phase, and multi-slave setups. Whether you are a student, hobbyist, or professional, this course will guide you through each step with clear explanations and practical examples to help you effectively use JTAG and SPI protocols in hardware design and testing. Additionally, students will explore real-world scenarios where JTAG aids in debugging and testing complex hardware systems, while SPI provides efficient data transfer between microcontrollers and peripheral devices. By the end of the course, participants will have a robust theoretical foundation, understanding the critical roles of JTAG in hardware testing and debugging and SPI in enabling seamless communication in embedded systems. The curriculum is designed to present complex concepts in a simplified manner, making it accessible to all learners and helping them build confidence in understanding and applying hardware protocols effectively.

Who this course is for:

Beginners who want to learn about hardware communication protocols from scratch.
Students pursuing electronics, computer engineering, or related fields who wish to enhance their practical knowledge.
Hobbyists and Makers interested in using JTAG and SPI for projects involving microcontrollers, FPGAs, or embedded systems.
Professionals seeking to add new skills in hardware testing, debugging, and communication protocols.
Anyone with a curiosity to learn about JTAG and SPI protocols, as no prior knowledge is required!

JTAG and SPI Protocol

What you'll learn

Explore related topics

Course content

JTAG Protocol4 lectures • 33min

SPI Protocol10 lectures • 51min

Requirements

Description

Who this course is for: