STMP1-SOM Schematics Overview
DDR3L Memory Interface
This section details the interface between the STM32MP157CAA3x microcontroller (U1A) and the DDR3L memory module (U2). It specifies the address, data, and control signal connections required for high-speed memory access.
Key Components:
- STM32MP157CAA3x Microcontroller (U1A)
- DDR3L Memory Module (U2, K4B4G1646D-BYK0)
Key Interfaces: Address Bus (S0SAx), Data Bus (S0SDQx), Control Signals (S0SCK_P, S0SCK_N, S0SCKE0, S0SDQM0, S0SDQM1, S0SCS0, S0SWE, S0SCAS, S0SRAS, S0SRST, S0SODT0), Power (1.35V_DDR, VDDQ, VSS).
STM32MP157CAA3x Microcontroller and Core Interfaces
This section covers the primary STM32MP157CAA3x microcontroller (U1B, U1D, U1G, U1H) and its various peripheral interfaces.
Key Interfaces:
- Storage: NAND, eMMC, QuadSPI interfaces for flash memory.
- T-Card (Micro SD Card): Interface for SD card connectivity.
- JTAG: Debugging interface.
- ADC/DAC: Analog-to-Digital Converter and Digital-to-Analog Converter interfaces.
- USB: High-speed USB ports (USB_DM, USB_DP).
- Other Peripherals: CAN bus, Camera interface, UART, I2C, SPI, GPIOs.
- Boot Configuration: Switches and resistors (BOOT0, BOOT1, BOOT2) to select boot modes (NOR, NAND, eMMC, SD-Card, UART/USB).
Display and Connectivity Interfaces
This section outlines the interfaces for display output and general connectivity.
Key Interfaces:
- LCD & HDMI: Signals for driving LCD panels and outputting to HDMI.
- Audio: Connections for audio input (microphone) and output (speakers/headphones), interfacing with the ES8388 codec.
- Debug UART: Dedicated UART port for debugging and serial communication.
- Ethernet: Physical layer interface for network connectivity.
- SOM to EVB Connectors: General-purpose connectors providing access to various MCU pins and interfaces for integration with evaluation boards.
Power Management and Supply
This section details the power supply circuitry, including voltage regulation, battery management, and power sequencing.
Key Components:
- Power Management IC (PMIC): AXP209 (U4) for managing power rails, battery charging, and system power-on.
- DC-DC Converters: Multiple step-down converters (e.g., SY8089AAAC, U3, U5) to generate various required voltages (1.2V_VDDCORE, 1.35V_DDR, 3.3V, etc.).
- LDO Regulator: AP1231-3.3V (VR1) for stable 3.3V output.
- Battery Management: Circuitry for Li-Ion battery charging and monitoring.
- IPS Discharge Circuit: Components for managing power discharge.
Key Voltages: +5V_EXT, +3.3V, 1.2V_VDDCORE, 1.35V_DDR, VBAT.
Audio Codec
This section focuses on the audio subsystem, featuring the ES8388 audio codec (U6).
Key Component: ES8388 Audio Codec (U6).
Key Interfaces: Connects to the STM32MP157CAA3x via I2C for control and SAI (Serial Audio Interface) for audio data transfer. Supports microphone input (MICIN1, VMIC) and headphone/line output (HPOUT1L, HPOUT1R, LOUT1, LOUT2, RIN1, RIN2).
