chip bring-up

**Chip Bring-Up / Silicon Validation** — the process of testing and validating the first fabricated silicon, verifying that the chip functions correctly and meets specifications before mass production. **Timeline** - Tapeout → fabrication → first silicon (2–3 months) - Bring-up team receives a handful of packaged chips - Must validate functionality and performance as quickly as possible **Bring-Up Sequence** 1. **Power-on**: Verify power supplies, check for shorts (excessive current = defect) 2. **Clock/PLL lock**: Verify clocks are running at expected frequencies 3. **JTAG/scan access**: Establish debug interface. Read chip ID registers 4. **Boot**: Load firmware, attempt basic boot sequence 5. **Peripheral validation**: Test each I/O interface (UART, SPI, DDR, PCIe) 6. **Functional testing**: Run test suites, benchmarks 7. **Performance characterization**: Measure max frequency, power, thermal behavior 8. **Corner testing**: Validate across voltage and temperature ranges **Common First-Silicon Issues** - Clock/PLL won't lock (analog corner case) - DDR training fails (signal integrity, timing) - Scan chain broken (manufacturing defect or design error) - Performance below target (unexpected RC parasitics) **Debug Tools** - Logic analyzer (external probing) - On-chip debug (JTAG, trace buffers, performance counters) - Silicon-to-RTL correlation: Compare actual behavior to simulation **Chip bring-up** is one of the most intense phases of a chip project — engineers work around the clock to find and categorize every issue before committing to production.