Section overview

Low-speed serial protocol timing, arbitration, chip-select behavior, FIFOs, DMA hooks, interrupts, and driver-visible contracts.

Topics

1. I2C Timing & Arbitration

2. SPI Modes & Chip-Select Rules

3. UART Flow Control

4. Peripheral Integration Debug

Related topics

• Protocols course hub

After this section

Try the section checkpoint, then review the Q&A

Section context

I2C/SPI/UART bugs are contract bugs: timing, reset value, IRQ type, and DMA watermark.

Illustrative review scenario

Illustrative review: a captured SPI transfer violated the flash device's chip-select hold time even though controller loopback passed. The external timing diagram—not the loopback result—defined the missing contract.