firmware

I²C / SPI Timing

I²C rise time, pull-up validation, cable length. SPI clock, bit/byte periods — timing diagram SVG.

I²C Inputs
Results
Rise Time t_r
Spec Limit1 µs
R_pull max (for C_bus)
R_pull min (~3 mA @ 3.3 V)1.1 kΩ
Max Cable Length (100 pF/m)
t_r = 0.8473 × R × C  ·  L_max ≈ (C_lim − C_bus) / 100 pF/m
Timing Diagram
SCLSDAStandard 100 kHzt_rSTARTDATASTOP