IBASE SMARC-EVK1 - Manual (Page 46)

20 SMARC Evaluation Kit
4.2.15. I2C Interface
I2C signals
Pin Signal Name I/O Type Power Rail Description
P121 I2C1_SCL_1V8 O OD 1.8V I2C Clock signal for Audio CODEC
P122 I2C1_SDA_1V8 I/O OD 1.8V I2C Data signal for Audio CODEC
S5 I2C2_SCL O OD 3.3V I2C Clock signal for Camera
S7 I2C2_SCL I/O OD 3.3V I2C Data signal for Camera
S139 I2C3_SCL O OD 3.3V I2C Clock signal for LCD Display
S140 I2C3_SCL I/O OD 3.3V I2C Data signal for LCD Display
S48 I2C4_SCL O OD 3.3V I2C Clock signal for PCI express
S49 I2C4_SCL I/O OD 3.3V I2C Data signal for PCI express
4.3. Layout recommendations
1.1 Signal impedance recommendation
Signal Group Impedance Layout Tolerance (±)
All signals, unless specified 50 Ω Single End 10%
PCIe, USB Diff signals 90 Ω Differential 10%
Diff signals: LVDS, SATA, HDMI, DDR, MIPI
(CSI & DSI), MLB, PHY IC to Ethernet
Connector 100 Ω Differential 10%