Astra™ Machina Micro SR100 Series Evaluation Platform Kit Rev C and later -

User Guide

Astra Machina Micro SR100 Series Evaluation Platform Kit RevC

Introduction

The Synaptics Astra™ SR100 Series of AI MCUs is designed to deliver high-performance, AI-Native, multimodal compute to consumer, enterprise, and industrial Internet of Things (IoT) workloads. Based on Arm® Cortex®-M55 cores with Helium™ technology and Arm Ethos™-U55 neural network processors (NPU), the MCUs feature multiple tiers of operation—performance, efficiency, low-power (LP) sensing, and always-on (AON)—that algorithmically deliver intelligence at every power level, to enable a new class of context-aware IoT devices. The AI-Native SR100 Series supports a rich set of peripherals and accelerators, including dual MIPI camera interfaces, image processing with encode and pre-roll, motion and voice activity detection engines, and industry-standard security. These features make it well-suited for streaming vision and audio processing applications at the IoT device edge.

The SR100 Series is a high-performance, ultra-low power, and small footprint Audio and Vision AI processor family.

Scope

This user guide describes the hardware configuration and functional details for the Astra Machina Micro SR100 Series Rev C and later Evaluation Platform Kit, and supported daughter cards, along with the bring-up sequence.

Definition of Board Components

• Astra Machina Micro SR100 Series: Combined system with Micro Development Kit and supported daughter cards.

• Micro Evaluation Platform Kit: Processor subsystem module with key components including SR110, QSPI, PSRAM and various standard hardware interfaces, buttons, headers, and power-in.

• Daughter card: Add-on boards for supporting various features such as connectivity, debug, images sensors and other flexible I/O options.

Astra Machina Micro Evaluation Platform Overview

This section covers system features, block diagrams, and board views of the Astra Machina Micro SR100 Series platform.

Figure 1. Dimensions: W x H = 59.55 mm x 51 mm

Features

The Astra Machina Micro SR100 Series Evaluation Platform Kit includes the following components:

• Main components on Machina Micro:

• Synaptics SR110 (122-FCCSP) Audio & Vision AI processor

• Debug IC: Synaptics SR100 (84-WCCSP)

• Storage: 128 Mbit QSPI NOR Flash

• PSRAM: 64 Mbit HyperRAM^™ x8, 200 MHz

• PMIC: Buck-Boost DC/DC for SR110 VBAT

• Highly sensitive ambient light sensor: TCS34303

• 3-axis accelerometer: MC3479

• M.2 E-key 2230 receptacle: Supports SDIO, UART, and PCM for Wi-Fi/BT modules

• 2 × USB 2.0 Type-C™ ports: One for SR110 Audio & Vision processor, other for Debug IC. Both provide system power.

• Push buttons for system reset, wake-up, and user control

• Slide switches for bootstraps, mute control, and power enable

• Daughter card interface options:

• 2 × MIPI CSI-2® 2-lane RX interfaces (1.5 Gb/s max bandwidth): CSI0 on Samtec™ connector (shared with DVP), CSI1 on 15-pin FPC connector

• 1 × MIPI CSI-2® TX interface (1.5 Gb/s max bandwidth) on 15-pin FPC connector

• SWD JTAG

• 2 × 20-pin headers with GPIOs are for additional application

• 4-pin header for UART debugging

• 3-pin header for PIR

• System power supply:

• USB Type-C

• 2-pin, 2.0 mm pitch header for 1-cell Li-ion battery

• 3-pin header for system power source selection

SR110 System Block Diagram

Figure 2. SR110 system block diagram

Top View of Astra Machina Micro SR110

Figure 3. Headers, Connectors, Chips (Top view)

Figure 4. LEDs, Pushbuttons, Switches (Top view)

Bottom View of Astra Machina Micro SR110

Figure 5. Connectors, Chips (Bottom view)

Astra Machina Board Control/Status & System I/O

This section covers boot-up procedures, LED status indicators, buttons, connectors, and pin-strap settings.

Bootup Mode

The Astra Machina Micro SR110 supports two bootup modes. ROM mode, SR110 receives program code from external host over host interface (UART, I2C Slave, SPI Slave), and normal application mode, which boots directly from the onboard QSPI flash.

• ROM mode: Set STRAP1 to High by closing switch of SW1-2,3. Then, power up the system and press the PMU_EN button, SW7 if SW1-1,4 is open position. Otherwise, pressing SW7 is not required.

• Normal mode: Set STRAP1 to Low, then power up the system and press the PMU_EN button, SW7 if SW1-1,4 is open position. Otherwise, pressing SW7 is not required.

The strap settings are listed in Table 1.

SM pin-strap and boot-up settings on the board

Pad Name	Strap Name	Setting Value	Resistor Stuffing + stuffed - removed	Description Rpu = OnChip Pull-up Rpd = OnChip Pull-down
I2S_DO	STRAP0	— 0* 1	— -R5 +R5	Straps for PLL frequency (If TEST_N=1) 0: 200 MHz 1: 24 MHz
SD0_CLK	STRAP1	— 0* 1	— SW1, pin2 OFF SW1, pin2 ON	Straps for booting up mode (If TEST_N=1) 0: boot from QSPI 1: boot from external host

• Indicates the default value.

LEDs

LED locations

Figure 6 shows the LED locations on Astra Machina Micro.

Figure 6. LED locations (Top View)

LED definitions

LED definitions on the board

LED	Color	LED Functions
D1	RED	User definable Red LED.
D2	Green	User definable Green LED.
D30	BLUE	light up when main SR110_USB and whole system are both powered.
D31	Green	light up when Li-ion battery is plugged-in and whole system are both powered.
D32	RED	light up when Debug IC USB is powered.
D33	Green	Flash during QSPI (SPI_CS0) access.

Hardware Manual Button Settings

Hardware push button settings definitions on the board

Switch Block	Type	Setting	Function
SW3 (RESET SR110)	Momentary Push-button	Push Release	Main SR110 Reset Key asserted Key de-asserted
SW4 (RESET Debug IC)	Momentary Push-button	Push Release	Debug IC Reset Key asserted Key de-asserted
SW7 (PMU_EN)	Momentary Push-button	Push Release	Enable main SR110 Key de-asserted
SW8 (User Button)	Momentary Push-button	Push Release	User push button (active low) Key de-asserted
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Figure 7. Locations of push buttons on Machina Micro board

Hardware Manual Slide Switch Settings

Hardware manual slide switch settings definitions on Machina

Switch Block	Pin #	Function	Description
SW1	1 2	USB wake up main SR110 Main SR110 STRAP1	OFF: Disconnect USBPWR to PMU_EN (Default) ON: Enable USBPWR to PMU_EN OFF: Boot from QSPI (Default) ON: Boot from external Host
SW2	1 2	Camera Mute Audio Mute	OFF: De-mute Camera (Default) ON: Mute Camera OFF: De-mute Audio (Default) ON: Mute Audio
SW5	1 2	DMIC Data DMIC Clock	OFF: Cut-off DMIC data from MCU (Default) ON: Link up DMIC data with MCU OFF: Cut-off DMIC clock from MCU (Default) ON: Link up DMIC clock with MCU
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Figure 8. Slide switch locations on Machina Micro board

Hardware Jumper Settings

This section outlines the board’s hardware jumper settings.

Hardware jumper settings definitions on the board

Ref Des	Type	Function	Configuration	Description
JP1	3x1, pitch 2.54mm header	System power source selection	1-2 2-3	System power is from USB Connector. (Default) System power is from Battery.
J29	2x2, pitch 2.54mm header	Power source Jumpers	1-2 3-4	Supply power to SR110 VBAT (Default) Supply Internal 1.8V LDO to source SR110 1V8 supply rail (Default)

Figure 9 shows the Header locations on the board.

Figure 9. Jumper Locations (Top View)

SR110 Machina Micro Platform Connectors

This section shows the connector locations on the board.

Connector locations on the Top Side

Figure 10. Connector Locations (Top Side)

Connector Locations on the Bottom Side

Figure 11. Connector Locations (Bottom Side)

Connector Definitions – Astra Machina Micro Platform

Connector definitions

Main Ref Des	Connecting Boards/Devices (Ref Des if any)	Function	Remarks
J2	CSI receiver module	CSI output	2 lane CSI output to FCC connector.
J4	M.2 2230 D/C	SDIO, PCM and UART	1x1/2x2 WiFi/Bluetooth card via SDIO and UART/PCM.
JP6	PIR module	PIR	For PIR input trigger.
J13	USB type-C Host	USB2.0 device, 5V power supply	Main SR110 USB2.0 device mode and system 5V input.
J14	USB type-C Host	USB2.0 device, 5V power supply and Debug Port	Debug IC USB2.0 device mode and system 5V input.
J20	Li-ion Battery	Battery power	Pitch 2.0mm header for 1 cell Li-ion Battery.
J21	Camera module	CSI1_RX	Raspberry-pi compatible 2-lanes CSI input.
J22	Off board debugger connect	SWD JTAG	Connector for off board debugger such as JLink for SR110
J23	Camera modules	CSI0_RX and DVP	2-lanes CSI input and 8bit DVP input
J24, J25	20 pin headers	General-purpose I/O pins interface	I2S, I2C, SPI, SDIO, UART, GPIOs, SPI, CIU, SWIRE
J26	Off board debugger connect	SWD JTAG	Connector for off board debugger such as Jlink for Debug IC.
J27	Off board Trace Module	SR110 debug + ETM	JTAG and Embedded Trace Macrocell (ETM) TRACECLK and TRACEDATA(n) signals.
J28	UART	UART0	Shared UART0 from main SR110 MCU and Debug IC.
J29	Power Sources	Power Source Jumpers	Apply 3.3V to VBAT and use internal 1.8V LDO to supply 1.8V input rail of the SR110

Stuffing Options for SR110 Machina Micro Platform Power Measurement

There are 0-ohm serial resisters on power rails that can be replaced with power meter for power measurement.

Check the corresponding power

Power Rail Name	Description	Stuffing Option	Implementation
VBAT	3.3V power for SR110_VBAT.	JP29 #1-2	Replace jumper with power meter
1.8V Supply Rail	Internal 1.8V LDO to supply 1.8V input rail of the SR110	JP29 #3-4	Replace jumper with power meter
SR110_VDDIO1P8	1.8V power that SR110 VDDIO needs.	R6	Replace R6 with power meter.
VDD_CORE	0.8V power that SR110 Core needs.	R8	Replace R8 with power meter.
V_DMIC	1.8V power that DMICs need	R1950	Replace R1950 with power meter.
VDDA	Analog power that SR110 needs.	R9	Replace R9 with power meter.
SYS_3V3_DVP	3.3V power supply to Camera module on J23.	R1904	Replace R1904 with power meter.
SYS_1V8_CSI_OUT	1.8V power supply to CSI transmitter on J2.	R1907	Replace R1907 with power meter.
SYS_3V3_CSI1	3.3V power supply to Camera module on J21.	R1906	Replace R1906 with power meter.
PWR_M2-KEYE_3V3	System power (4.8V~2.8V) supply to WiFi module on J4	R1852	Replace R1852 with power meter.
SYS_1V8_JTAG	1.8V power supply to JTAG debug.	R1861	Replace R1861 with power meter.
DBG_SYS_1V8	1.8V power that Debug IC sus-system needs.	R177	Replace R177 with power meter.
SYS_PWR_SRC	Total power (4.8V~2.8V) that main SR110 system needs.	JP1 #1-2 JP1 #2-3	If system power comes from USB, attach two probes of power meter to JP1#1 and #2. If system power comes from Battery, attach two probes of power meter to JP1#2 and #3.
SR110_VDDH_USB	1.8V power for SR110 USB	R1858	Replace R1858 with power meter
QSPI_1V8	1.8V power for QSPI	R1947	Replace R1947 with power meter
PWR_M2-KEYE_VIO	1.8V VIO Power to M2	R1975	Replace R1975 with power meter.
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Figure 12. Probe points (Top side)

Figure 13. Probe points (Bottom side)

Daughter Cards

A set of daughter cards supplements (not included) the Astra Machina system with a range of extensible and configurable functionalities including Wi-Fi and Bluetooth connectivity, debug options and general purpose I/O. Details of currently supported daughter cards are described in this section.

Debug Board

Different kinds of debug interfaces are routed out for users to communicate with the SR110 system. The 20-pin SR110 debug + ETM header, J27 can be used to access the Embedded Trace Macrocell (ETM) TRACECLK and TRACEDATA(n) signals. The four TRACEDATA signals provide a high-speed data path for capturing instructions.

J22, 10-pin SWD JTAG header, allows connection to a 10-pin ARM debug connector for the debugging application SR110.

Users may communicate with SR110 over UART on a PC host by using a UART to USB cable commonly available. For a list of qualified parts, see the Astra Machina webpage.

https://synacsm.atlassian.net/jira/servicedesk/projects/CASE/knowledge/articles/39780364?spaceKey=ASDKB

As an option, the debug board also provides such bridging function based on the Silicon Labs CP2102. A virtual COM port driver is required, and can be downloaded from the following link and installed on the host PC:

https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

UART on the Machina Micro board and the PC host USB are digitally isolated, with no direct conductive path, eliminating ground loop and back-drive issues when either is powered down.

USB device port is also available for PC host to communicate directly though type-C to type-A cable.

Figure 14 shows debug board connectivity facilitating UART and JTAG communications.

1. UART to USB adaptors/modules mentioned in the Knowledge base support only TTL 3.3V UART signals. UART signals of SR110 Machina Micro Platform are 1.8V CMOS. CP2102 and CH340G are not compatible with SR110 Machina Micro.

Figure 14. Debug board connectivity for UART and JTAG

Onboard Debug and Programming Interface via Debug IC, SR100 (SWD + UART)

The Astra Machina Micro platform incorporates a flexible and robust debug architecture that offers an onboard option to program and debug the SR110 SoC using Serial Wire Debug (SWD). This is achieved through the inclusion of a dedicated debug IC, specifically the SR100, which serves as a bridge between external PCs and the SR110. The SR100 acts as a USB to SWD bridge, with the PC connected over USB, and the SR110 connected via SWD. This emulates the behavior of widely used debug probes such as the SEGGER J-Link.

By leveraging this built-in debugging path, the system enables seamless access to the SR110’s core and peripheral registers for firmware development, bring-up, and system-level debugging—without the need for external debug hardware connections directly to the SoC.

In addition to acting as a USB to SWD bridge the debug SR100 also acts as a USB to UART bridge. The firmware on the SR100 uses the USB CDC class to emulate two com ports. After connecting a PC to the debug SR100 USB (J14), two com ports enumerate on the PC. The first com port is for UART0, and the second for UART1.

UART0 can be used to program the SR110 when STRAP1 is set to ROM mode. When STRAP1 is not in ROM mode UART0 can also be used to communicate with the Host API running on SR110, if the FW configures UART0 for the Host API communication interface.  UART1 can be used to capture logs from the SR110.

Figure 15. DAP Block Diagram

Table 8. Serial Wire Debug (TCK/TMS) Signal Paths: Debug IC ↔ SR110

SWD	Debug IC	SR110	J22 Header
TCK	U19-H12 (GPIO[6])	U2-C17	J22-4
TMS	U19-K12 (GPIO[7])	U2-B18	J22-2
RSTn	U19-H6 (GPIO[27])	U2-J1	—

M.2 Card

An M.2 E-Key socket J4 is provided for a variety of modules in the M.2 form factor. Typical applicable modules support Wi-Fi/BT devices with SDIO interfaces.

Available module:

• Ampak AP12611_M2P with SYN43711 1x1 WiFi6E/BT5.3 1x1 over SDIO on M.2 adaptor (not included).

Figure 16. WiFi module plugged in M.2 slot

Camera Module

Two camera interfaces DVP and CSI0 (not included) are both routed out to J23, that allowed developer to switch their own camera module which has the matched pin sequence. Machina Micro Evaluation Platform can do person detection with the default attached camera module OV02C10, which is mounted on the platform through a small Samtec daughter card. Please take care about the connecter pin definition between module and daughter card, daughter card pin #24 should connect to module’s pin #12, instead of pin #1 to pin #1.

Figure 17. Camera daughter card with module OV02C10 on Machina Micro board

Figure 18. Connector between Camera daughter card and module OV02C10

General Purpose 20-pin Header

Two general-purpose 20-pin GPIO headers with a 0.1-inch (2.54 mm) pin pitch are located on the left and top edges of the Machina Micro board. All general-purpose I/O pins operate at 1.8V and can be configured in software to support a variety of alternate functions.

For detailed configuration options, refer to the SR100 Series Datasheet.

Figure 19. General Purpose J24, 20-Pin Header with Signal Mapping

Figure 20. General Purpose J25, 20-Pin Header with Signal Mapping

Pin Demuxing for Standard Interface Configuration

This section covers pin-demuxing configuration for the Machina Micro SR110 board.

Pin Multiplexer Modes

Ball Name	NetNames	Reference Destination	Function	Pin Multiplexer Mode*	Notes
AUDIO_MUTE	SR110_AUDIO_MUTE	SW2-1,4	Audio Mute	ALT 0 (GPIO); Any	Mute
CAMERA_MUTE	SR110_CAMERA_MUTE	SW2-2,3	Camera Mute	ALT 0 (GPIO); Any
CIU_D3	SR110_GPIO10.CIU_D3	J23-31 J25-2	DVP Connector, D3 20 Pin Header	ALT 1 ALT 0 (GPIO); Any	— —
CIU_D6	SR110_GPIO13. CIU_D6.DM0_CLK_B	J23-17 SW5-1,4 J25-17 U19-H8	DVP Connector, D6 Connect DMIC CLK 20 Pin Header Logger UART TX to Debug IC	ALT 1 ALT 2 ALT 0 (GPIO); Any ALT 3	Cannot simultaneously operate DVP, DMIC, and UART1 Logger. Only one can run at a time
CIU_D7	SR110_GPIO14.CIU_D7.DM0_DATA_B	J23-15 SW5-2,3 JP25-18 U19-G9	DVP Connector, D7 Connect DMIC DATA 20 Pin Header Logger UART RX to Debug IC	ALT 1 ALT 2 ALT 0 (GPIO); Any ALT 3	Cannot simultaneously operate DVP, DMIC, and UART1 Logger. Only one can run at a time
CIU_VSYNC	SR110_GPIO4.CIU_VSYNC_A	J23-35 J25-5 J4-34 J23-40	DVP Connector, VSYNC 20 Pin Header M.2 UART_CTS (BT/BLE) DVP Connector, VSYNC	ALT 1 ALT 0 (GPIO); Any ALT 3 ALT 1	Cannot simultaneously operate DVP and M.2 UART (BT/BLE) Not populated by default
CLK32K_IN	SR110_GPIO40. CLK32KIN	J24-17	20 Pin Header	ALT 0 (GPIO); Any	—
CLKOUT0	SR110_GPIO41 .CLKOUT0	J23-7 J24-15	DVP Connector, Clock 20 Pin Header	ALT 1 ALT 0 (GPIO); Any	— —
CSI_OUT_CN	SR110_CSI_OUT_CN	J2-8	—	—	CSI_OUT
CSI_OUT_CP	SR110_CSI_OUT_CP	J2-9	—	—
CSI_OUT_D0N	SR110_CSI_OUT_D0N	J2-2	—	—
CSI_OUT_D0P	SR110_CSI_OUT_D0P	J2-3	—	—
CSI_OUT_D1N	SR110_CSI_OUT_D1N	J2-5	—	—
CSI_OUT_D1P	SR110_CSI_OUT_D1P	J2-6	—	—
CSI0_IN_CN	SR110_CSI0_IN_CN	J23-22	—	—	CSI0_IN
CSI0_IN_CP	SR110_CSI0_IN_CP	J23-20	—	—
CSI0_IN_D0N	SR110_CSI0_IN_D0N	J23-16	—	—
CSI0_IN_D0P	SR110_CSI0_IN_D0P	J23-14	—	—
CSI0_IN_D1N	SR110_CSI0_IN_D1N	J23-28	—	—
CSI0_IN_D1P	SR110_CSI0_IN_D1P	J23-26	—	—
CSI1_IN_CN	SR110_CSI1_IN_CN	J21-8	—	—	CSI1_IN
CSI1_IN_CP	SR110_CSI1_IN_CP	J21-9	—	—
CSI1_IN_D0N	SR110_CSI1_IN_D0N	J21-2	—	—
CSI1_IN_D0P	SR110_CSI1_IN_D0P	J21-3	—	—
CSI1_IN_D1N	SR110_CSI1_IN_D1N	J21-5	—	—
CSI1_IN_D1P	SR110_CSI1_IN_D1P	J21-6	—	—
GPIO5	SR110_JTAG_TRSTN_A .CIU_HSYNC.GPIO5	J25-5 J23-37 J4-36 J22-10	20 Pin Header DVP Connector, HSYNC M.2 UART_RTS (BT/BLE) JTAG TRST	ALT 2 ALT 1 ALT 3 ATL 0	Cannot simultaneously operate DVP and M.2 UART (BT/BLE) Cannot run JTAG with DVP or M.2UART
GPIO6	SR110_GPIO6.CIU_BCLK.SPI_SLV_CLK_B	J25-7 J23-38 J23-14	20 Pin Header DVP Connector, BCLK OV2C_D0p/SCLK	ALT 0 (GPIO); Any ALT 1 ALT2	— — Not populated by default
GPIO7	SR110_GPI O7.CIU_D0.SPI_SLV_MOSI_B	J25-10 J23-39 J23-16	20 Pin Header DVP Connector, D0 OV2C_D0n/SDAT	ALT 0 (GPIO); Any ALT 1 ALT 2	— — Not populated by default
GPIO8	SR110_JTAG_TDI_A.CIU_D1.GPIO8.SPI_SLV_CS_B	J23-40 J25-8 J22-10	DVP Connector, D1 20 Pin Header JTAG_TDI	ALT 1 ALT 2 ALT 0 (GPIO); Any	DVP cannot run while JTAG is active
GPIO9	SR110_JTAG_TDO_A.CIU_D2.GPIO9.SPI_SLV_MISO_B	J23-33 J22-6 J25-9	DVP Connector, D2 JTAG_TDO 20 Pin Header	ALT 1 ALT 0 ALT 2 (GPIO); Any	DVP cannot run while JTAG is active
I2C_SLV_SCLI2C_PMU_SCL I3C_SLV_SCL	SR110_GPIO45.I2C_PMU_SCL.UART0_TX_C	J2-14 J4-32 J24-13	I2C Slave over RPI connector M.2 UART RX (BT/BLE) 20 Pin Header	ALT 1 ALT 2 ALT 0 (GPIO); Any	M.2 UART and RPI Connector I2C Slave cannot operate simultaneously
I2C_SLV_SDAI2C_PMU_SCL I3C_SLV_SCL	SR110_GPIO44.I2C_PMU_SDA.UART0_RX_C	J2-15 J4-22 J24-14	I2C Slave over RPI connector M.2 UART RX (BT/BLE) 20 Pin Header	ALT 1 ALT 2 ALT 0 (GPIO); Any	M.2 UART and RPI Connector I2C Slave cannot operate simultaneously
I2S_BCLK	SR110_GPIO17. I2S_BCLK	J27-20 J4-8 J24-3	Trace Data I2S to M.2 20 Pin Header	ALT 2 ALT 1 ALT 0 (GPIO); Any	I2S and Trace cannot operate simultaneously
I2S_DI	SR110_GPIO20.I2S_DI	J4-14 J27-14 J24-24	I2S to M.2 Trace Data 20 Pin Header	ALT 1 ALT 2 ALT 0 (GPIO); Any	I2S and Trace cannot operate simultaneously
I2S_D0	SR110_GPIO19.I2S_DO	J4-14 J27-16 J24-5	I2S to M.2 Trace Data 20 Pin Header	ALT 1 ALT 2 ALT 0 (GPIO); Any	I2S and Trace cannot operate simultaneously
I2S_FSYNC	SR110_GPIO18.I2S_FSYNC	J4-10 J27-18 J24-4	I2S to M.2 Trace Data 20 Pin Header	ALT 1 ALT 2 ALT 0 (GPIO); Any	I2S and Trace cannot operate simultaneously
I2C0_MS_SCL	SR110_GPIO15.I2C0_MS_SCL	U7-3 J23-13 U16-19 U14-3 U31-1 U26.2 J25-3 SW5-1,4	Level Translator control of camera c onnected via RPI connector DVP connector, I2C camera control Port Expander ALS IMU RTC 20 Pin Header Connect DMIC CLK	ALT 1 ALT 1 ALT 1 ALT 1 ALT 1 ALT 1 ALT 0 (GPIO); Any ALT3	— — — Not populated by default OV2C_D0p/SCLK — — —
I2C0_MS_SDA	SR110_GPIO16.I2C0_MS_SDA	U7-4 J23-11 U16-20 U14-2 U31-4 U26.3 J25-4 SW5-2,3	Level Translator control of camera c onnected via RPI connector DVP connector, I2C camera control Port Expander ALS IMU RTC 20 Pin Header Connect DMIC DATA	ALT 1 ALT 1 ALT 1 ALT 1 ALT 1 ALT 1 ALT 0 (GPIO); Any ALT3	— — — Not populated by default Not populated by default — — —
JTAG_TCK	SR110_GPIO31. JTAG_TCK	J22-4 U19-H12	Debug Header SWD to Debug IC	ALT 0 (GPIO); Any ALT 0 (GPIO); Any	— —
JTAG_TMS	SR110_GPIO32. JTAG_TMS	J22-2 U19-K12	Debug Header SWD to Debug IC	ALT 0 (GPIO); Any ALT 0 (GPIO); Any	— —
PMU_EN	SR110_PMU_EN	SW1-1,4			If on PMU_EN will go high when USB is c onnected
RESET_N	SR110_RSTn	U16-24 J22-7 U19-H6	Port Expander Debug Header Debug IC	ALT 0 (GPIO); Any ALT 0 (GPIO); Any ALT 0 (GPIO); Any	Not populated by default
SD0_CLK	SR110_GPIO26 .SD0_CLK	SW1-2,3 J27-12 J24-8	Strap 1 Trace Data 20 Pin Header	STRAP 1 ALT 3 ALT 0 (GPIO); Any	Change programming mode — —
SD0_CMD	SR110_GPIO25 .SD0_CMD	J24-7 J4-54	20 Pin Header M2- KEYE_W_DISABLE2n	ALT 0 (GPIO); Any ALT 0 (GPIO); Any	— —
SD0_D0	SR110_GPIO27.SD0_D0	J24-9	20 Pin Header	ALT 0 (GPIO); Any	—
SD0_D1	SR110_GPIO28.SD0_D1	J24-10	20 Pin Header	ALT 0 (GPIO); Any	—
SD0_D2	SR110_GPIO29.SD0_D2 .DM1_CLK	J24-11	20 Pin Header	ALT 0 (GPIO); Any	—
SD0_D3	SR110_GPIO30 .SD0_D3. DM1_DATA	J24-12	20 Pin Header	ALT 0 (GPIO); Any	—
SD1_CLK	R110_GPIO35 .SD1_CLK	J4-9	M.2 SDIO	ALT 1	—
SD1_CMD	SR110_GPIO34 .SD1_CMD	J4-11	M.2 SDIO	ALT 1	—
SD1_D0	SR110_GPIO36.SD1_D0	J4-13	M.2 SDIO	ALT 1	—
SD1_D1	SR110_GPIO36.SD1_D1	J4-15	M.2 SDIO	ALT 1	—
SD1_D2	SR110_GPIO36.SD1_D2	J4-17	M.2 SDIO	ALT 1	—
SD1_D3	SR110_GPIO36.SD1_D3	J4-19	M.2 SDIO	ALT 1	—
SPI_MSTR_CLK	SR110_GPIO22.SPI_MSTR_CL K.CIU_D5	J23-19 J25-11	DVP Connector, D5 20 Pin Header	ALT 3 ALT 0 (GPIO); Any	— —
SPI_MSTR_CS	SR110_GPIO21.SPI_MSTR_C S.CIU_D4	J2512 J23-23	DVP Connector, D4 20 Pin Header	ALT 3 ALT 0 (GPIO); Any	— —
SPI_MSTR_MISO	SR110_GPIO24.SPI_MSTR_M ISO.I2C1_MS_SDA. UART1_RX	U14-2 (TCS34303) U31-4 (MC3479) J23-11 J25-13	ALS Sensor I2C IMU I2C DVP connector, I2C camera control 20 Pin Header	ALT 3 ALT 3 ALT 3 ALT 0 (GPIO); Any	— — Not populated by default —
SPI_MSTR_MOSI	SR110_GPIO23.SPI_MSTR_M OSI.I2C1_MS_SCL. UART1_TX	U14-3 (TCS34303) U31-1 (MC3479) J25-14	ALS Sensor I2C IMU I2C 20 Pin Header	ALT 3 ALT 3 ALT 0 (GPIO); Any	— — —
SPI_SLV_CLK	SR110_AON_GPO1	SYS_PWR_MOS_EN (R1865) J24-16	System Power Enable 20 Pin Header	ALT 5 ALT 0 (GPIO); Any	— —
SPI_SLV_CS	SR110_GPIO3. AON_GPI1	U16-22(PI4IOE5V6416ZDEX)	Port Expander Int	ALT 0 (GPIO); Any	—
SPI_SLV_MISO	SR110_GPIO0. UART0_TX_A.TESTn	J28-2 U19-C9	UART Header Debug IC	ALT 1 ALT 1	ROM Programming UART connect to Debug IC
SPI_SLV_MOSI	SR110_GPIO1.UART0_RX_A	J28-3 R12 U19-B10	UART Header 4.7k Pull-Up to 1.8V Debug IC	ALT 1 ALT 1 ALT 1	ROM Programming — UART connect to Debug IC
SWIRE_CLK	SR110_GPIO42.SWIRE_CLK	J23-10 J25-15 U7-3 (PCA9306JKZ) U31-1 (MC3479) U14-3 (TCS34303) U16-19 (PI4IOE5V6416ZDEX) J23-13	DVP Connector 20 Pin Header I2C1_MS_SDL_B I2C1_MS_SDL_B I2C1_MS_SDL_B I2C1_MS_SDL_B DVP Connector	ALT 3 ALT 0 (GPIO); Any ALT 3 ALT 3 ALT 3 ALT 3 ALT 3	— — — — — — —
SWIRE_DATA	SR110_GPIO43.SWIRE_DATA	J4-54 J25-16 U7-4 (PCA9306JKZ) U31-4 (MC3479) U14-2 (TCS34303) U16-20 (PI4IOE5V6416ZDEX) J23-11	DVP Connector 20 Pin Header I2C1_MS_SDA_B I2C1_MS_SDA_B I2C1_MS_SDA_B I2C1_MS_SDA_B DVP Connector	ALT 3 ALT 0 (GPIO); Any ALT 3 ALT 3 ALT 3 ALT 3 ALT 3	— — — — — — —
USB_HS_DN	SR110_USB_HS_DN	J13 (USB Conn)	—	—	—
USB_HS_DP	SR110_USB_HS_DP	J13 (USB Conn)	—	—	—
VBAT	SR110_VBAT_0	JP29-1 SW7 (Push Button: PMU EN)	— —	— —	— —
VDDH_USB	SR110_VDDH_USB	U28-1 SW1-1,2 ( PMU_EN)	— —	— —	— —
XSPI_CLK	SR110_xSPI_CLK	U4- B2(W956D8MBYA5I) U5-6 (GD25LQ128EWIGR)	— —	— —	Not stuff by default —
XSPI_CLKN	SR110_x SPI_CLKn	U4- B1(W956D8MBYA5I)	—	—	Not populated by default
XSPI_CS0N	SR110_x SPI_CS0n	U5-1 (GD25LQ128EWIGR)	—	—	—
XSPI_CS1N	SR110_x SPI_CS1n	U4(W956D8MBYA5I)	—	—	Not populated by default
XSPI_DATA0	SR110_xSPI_D0	U5-5 (GD25LQ128EWIGR) U4-D3 (W956D8MBYA5I)	— —	— —	— Not populated by default
XSPI_DATA1	SR110_xSPI_D1	U5-2 (GD25LQ128EWIGR) U4-D2 (W956D8MBYA5I)	— —	— —	— Not populated by default
XSPI_DATA2	SR110_xSPI_D2	U5-3 (GD25LQ128EWIGR) U4-C4 (W956D8MBYA5I)	— —	— —	— Not populated by default
XSPI_DATA3	SR110_xSPI_D3	U5-7 (GD25LQ128EWIGR) U4-D4 (W956D8MBYA5I)	— —	— —	— Not populated by default
XSPI_DATA4	SR110_xSPI_D4	U4(W956D8MBYA5I)	—	—	External xSPI, HyperRAM Rev B: Available. Rev C: DNS (Desing not Stuff)
XSPI_DATA5	SR110_xSPI_D		—	—
XSPI_DATA6	SR110_xSPI_D6		—	—
XSPI_DATA7	SR110_xSPI_D7		—	—
XSPI_DQS	SR110_xSPI_DQS		—	—

GPIO Expanders Over I2C

Due to the considerable number of functionalities covered by Machina Micro SR110 platform, most of the SR110 digital pins that have GPIO/GPO pin-demux options are used for other functions. As such, GPIO expanders are used extensively to supplement system control purposes.

GPIO expanders usage

Expander GPIO/GPO	I2C#	Voltage	Direction	Function	GPIO S ignaling
GPIO0_0	I2C0 (0x20)	1.8V	OUT	User definable Green LED	0: OFF 1: ON
GPIO0_1	I2C0 (0x20)	1.8V	OUT	User definable Red LED	0: OFF 1: ON
GPIO0_2	I2C0 (0x20)	1.8V	OUT	PWR_ON_CSI1	0: Power ON CSI1 1: Power OFF
GPIO0_3	I2C0 (0x20)	1.8V	IN/OUT	GPIO for CSI1	0: reserved 1: reserved
GPIO0_4	I2C0 (0x20)	1.8V	IN	Interrupt1 (sample + motion) from IMU	0: interrupt occur 1: no interrupt
GPIO0_5	I2C0 (0x20)	1.8V	IN	Interrupt2 (FIFO) from IMU	0: interrupt occur 1: no interrupt
GPIO0_6	I2C0 (0x20)	1.8V	IN	Interrupt from ALS	0: interrupt occur 1: no interrupt
GPIO0_7	I2C0 (0x20)	1.8V	OUT	Power down WiFi	0: power down 1: power up
GPIO1_0	I2C0 (0x20)	1.8V	OUT	enable system 3.3V LDO	0: disable 1: enable
GPIO1_1	I2C0 (0x20)	1.8V	OUT	enable system 2.8V LDO	0: disable 1: enable
GPIO1_2	I2C0 (0x20)	1.8V	OUT	Reset PSRAM	0: trigger reset 1: release reset
GPIO1_3	I2C0 (0x20)	1.8V	OUT	User definable button	0: assert 1: de-assert
GPIO1_4	I2C0 (0x20)	1.8V	OUT	Power ON CSI out	0: Power OFF 1: Power ON
GPIO1_5	I2C0 (0x20)	1.8V	OUT	Power ON DVP	0: power down DVP 1: power up DVP
GPIO1_6	I2C0 (0x20)	1.8V	IN	Wake up from WiFi/BT	0: wake-up trigger 1: no trigger
GPIO1_7	I2C0 (0x20)	1.8V	OUT	Host wake up BT	0: wake-up trigger 1: no trigger

I2C Bus

This section describes the Astra Machina’s usage of the I²C bus, the equivalence of SR110’s Two Wire Serial Interface (TWSI) bus.

I2C bus descriptions

I2C/TWSI Bus	Device	Part Number	Ref Des	Target Address (7-bit)	Location
I2C1	IC GPIO Expander I2C 8-Bit CSI0 control CSI1 control RTC IC IMU sensor IC ALS sensor IC	PI4IOE5V6416ZDEX Not applicable Not applicable BU9873NUX-TTR MC3479 TCS34303	U16 J23 J21 U26 U31 U14	0x20 0xXX 0xXX 0x32 0x4C 0x39	SR110 Platform
I2C0	External device connects to 20-pin Header	Not applicable	J25	0xXX

Bringing Up the SR100 Series Evaluation Platform

Connecting External Components and Performing Hardware Testing

Perform the following steps to connect the external components to the SR100 Series Evaluation Platform:

1. Connect J13 and PC through a USB type-C cable.

2. Add a jumper cap to short JP1 pin 1-2.

3. Make sure two jumper caps are put on J29 to short pin1-2, another to short pin3-4.

If there is no short issue, power up the system and check voltages as shown in Figure 21 and Table 12, the LED status is shown in Table 2.

Figure 21. Short and voltage check points

Table 12. Short and voltage check points using any test point for ground

Ref Des	Form	Signal	Voltage
TP9	SMD pad	SR110_VDDH_USB	3.3V +/- 2% [3.234,3.366]
TP12	SMD pad	SR110_1V8_IN	1.8V +/- 2% [1.764,1.836]
TP13	SMD pad	SR110_VDDIO1P8	1.8V +/- 2% [1.764,1.836]
TP15	SMD pad	SR110_VDD_CORE_IN	0.8V +/- 2% [0.784,0.816]
J29 pad1	DIP pad	SR110_VBAT_0	3.3V +/- 2% [3.234,3.366]
D20 pad1	SMD pad	USBC_PWR	4.5V~5.2V
JP1 pad 3	DIP pad	BATT_PWR	2.8V~4.2V
R1844 pad1	SMD pad	SYS_PWR_SRC	2.8V~5V
R1881 pad1	SMD pad	SYS_3V3	3.3V +/- 2% [3.234,3.366]
R1905 pad2	SMD pad	SYS_1V8	1.8V +/- 2% [1.764,1.836]
J23 pad2	SMD pad	SYS_2V8	2.8V +/- 2% [2.744,2.856]

References

The following document is applicable to the SR110 Machina Micro:

• Astra™ Machina Micro SR100 Series Evaluation Platform Kit Rev B - User Guide

  (PN: 511-001445-01)
• Astra™ Machina Micro SR100 Series Evaluation Platform Kit Rev C and later - User Guide

  (PN: 511-001445-02)

• SR100 Series High-Performance Context-Aware AI MCUs Datasheet (PN: 505-001430-01)