Hardware User Manual for S32K148-based T-BOX/GP-ECU Reference Design

1. Functional Features

The S32K148-based T-BOX/GP-ECU reference design utilizes the S32K1xx series, NXP's latest automotive microcontroller family, specifically the S32K148 model with maximum resources. It leverages the rich on-chip hardware peripherals and software development kits to provide users with a ready-to-verify reference design evaluation platform for automotive T-BOX solutions.

Key features include:

• Core MCU: FS32K148UJT0VLQT, featuring an ARM Cortex-M4F core with DSP instructions and hardware IEEE 1577 single-precision floating-point unit, capable of operating at frequencies up to 112 MHz. It includes 2MB Flash, 256KB SRAM, and 4KB high-performance analog EEPROM.
• Rich Communication Interfaces:
  • 3 CAN interfaces, supporting CAN-FD.
  • 3 UART interfaces, with two supporting LIN (extended via SBC—UJA113x).
  • 1 x 100M-base TX1 Gigabit Automotive Ethernet interface (TJA1101 as transceiver).
• Audio Codec: SGTL5000 audio codec chip connected via I2S interface for audio capture and output.
  • Supports 1x stereo input (LINE IN) and 1x MIC input.
  • 1x gain-amplified headphone output and 1x stereo output (LINE OUT).
  • Integrated PLL clock multiplier.
  • Integrated digital audio processor supporting surround sound, tone control, and various equalizations.
  • I2S interconnect communication interface.
• External Flash: 8MB QSPI Flash memory expansion.
• T-BOX Function Expansion Module Interfaces:
  • 1 UART BLE Bluetooth module interface.
  • 1 UART GPS positioning module interface.
  • 1 UART 3G/4G communication module interface.
• User Inputs: 2 user buttons, 2 capacitive touch sensor inputs.
• Indicators: 3-color RGB LED.
• Analog Input: 1x sliding potentiometer ADC input.
• 23-pin ECU Connector: Provides a dedicated 23-pin automotive ECU connector for extended communication and external signal input/output.
  • 2 x external ADC inputs.
  • 2 x HS PWM outputs.
  • 2 x PWM inputs.
• S32K148EVB Compatibility:
  • Provides Arduino™ UNO compatible expansion interfaces.
  • Can directly run SDK example projects.

A physical photo of the hardware reference design is provided.

2. Hardware Block Diagram Introduction

The main functional module interconnection block diagram for this reference design is shown.

The design is powered by a 12V automotive battery/ignition signal (IGN). The integrated 12V to 5V LDO within the SBC-UJA1132 provides the necessary 5V power for the S32K148 and other on-chip functional modules, with a maximum supply capability of 500 mA. An additional protected 100 mA 5V LDO output is available for powering external sensor modules. The SBC also provides one CAN bus transceiver (supporting up to 2 Mbit/s CAN-FD) and two LIN bus transceivers (supporting up to 100 mA CAN-FD).

The BLE Bluetooth, GPS positioning, and 3G/4G communication modules for the T-BOX reference design communicate with the S32K148 via UART, using 2.54 mm pitch pin headers for interconnection, facilitating seamless switching between T-BOX and GP-ECU function evaluation.

To ensure compatibility with both 3.3V and 5V systems, this design incorporates numerous level-shifting chips for 3.3V to 5V and 5V to 3.3V conversions.

3. Functional Module Circuit Introduction

3.1 Power Circuit

The power circuit of this design consists of two parts.

The first part is the 5V generation circuit using the SBC—UJA1132, with the schematic shown. It is powered by a 12V battery voltage and provides two 5V outputs:

• V1 (P5V0_V1SBC) can supply a maximum of 500 mA.
• V2 (PVEXT_SBC) provides a protected maximum of 100 mA, suitable for powering external ECU modules.

The second part is the DC-DC power circuit using AP1509 to generate 3.3V. It is powered by the 12V VBAT and outputs 3.3V (P3V3_SW), capable of providing a maximum current of 2A.

The supply voltage (VDD) for the S32K148 and peripheral modules is set by J9, allowing selection between a 3.3V system (P3V3_SW) or a 5V system (P5V0). By default, J9 pins 1 and 2 are shorted, operating the S32K148 in a 3.3V system.

Through J11/R77 and R78, the system supply voltage VDD is divided into VDD_MCU specifically for the S32K148 and VDD_MCU_PERH for peripheral modules. This division facilitates testing of the S32K148's low-power static current.

3.2 CAN Bus Interface Circuit

This reference design connects all three FlexCAN interfaces of the S32K148 to transceivers.

FlexCAN0 is connected to the CAN bus transceiver integrated into the UJA1132 via pins PTE4/PTE5.

FlexCAN1 is connected to the TJA1044 CAN bus transceiver via pins PTC6/PTC7 and is controlled by PTC11 for the standby low-power mode (high level active).

FlexCAN2 is connected to the TJA1043 CAN bus transceiver via pins PTB12/PTB13 and is connected to the TJA1043's EN (high level active) and STB_n (low level active) pins PTB11 and PTB15, respectively, to control its operating and low-power modes.

All three CAN bus interfaces are connected to the 23-PIN ECU connector for communication with other ECUs. Please refer to section 3.12 for specific signal assignments.

3.3 LIN Bus Interface Circuit

The S32K148's LPUART0 and LPUART2 are connected to the two LIN transceivers integrated into the UJA1132 via PTA2/PTA3 and PTA8/PTA9, respectively, providing LIN bus communication interfaces.

These two LIN bus interfaces are connected to the 23-PIN ECU connector for communication with external ECUs. Please refer to section 3.12 for specific signal assignments.

3.4 Ethernet Interface Circuit

The S32K148's ENET is connected to the TJA1101 in MII mode, using a local 25 MHz crystal oscillator for the reference clock. The physical address is preset via pin pull-up/down resistors to 0b'00101.

The output is a differential signal pair ENET_TRX_P/ENET_TRX_N, which is routed to the 23-PIN ECU connector for communication with external ECUs. Please refer to section 3.12 for specific signal assignments.

3.5 QSPI External Flash Memory Circuit

The S32K148 integrates a QSPI interface operating at 80 MHz, supporting external Flash expansion. This design includes an 8MB QSPI Flash—MX25L6433FM2R.

Note: The MX25L6433FM2R only supports a 3.3V operating voltage. Therefore, the S32K148's QSPI interface has been converted via level-shifting chips. This allows the S32K148 to operate in a 5V system even when using this QSPI external Flash.

By default, R162, R178, R188, R192, R195, and R201 are DNP (Do Not Populate), while R162, R177, R179, R190, R194, and R196 are soldered. This means PTD7, PTC2, PTD10, PTD12, PTD13, and PTC3 are connected to the Ethernet transceiver (TJA1101). To use the QSPI external Flash, R162, R177, R179, R190, R194, and R196 must be DNP, and R162, R178, R188, R192, R195, and R201 must be soldered.

3.6 BLE Bluetooth Module Interface Circuit

The selected BLE Bluetooth module is HC-08, which only supports 3.3V operation. The S32K148's LPUART0 (PTB0/PTB1) is connected to it via a level-shifting chip and powered through the 4-PIN J26 connector.

3.7 GPS Positioning Module Interface Circuit

The GPS positioning module used in this design is the NEO-6M, operating at 3.3V and using UART communication. The S32K148's LPUART1 (PTCB/PTC9) and PTD4 are connected to it via level-shifting chips through the 5-PIN J28 connector.

3.8 3G/4G Communication Module Interface Circuit

The selected 3G/4G communication module is the USR-LTE-7S4. It connects to the S32K148's LPUART2 (PTD17/PTE12) via dual-row 1x12-PIN connectors J25 and J27. Its reset control (M_RESET_N, active low), reload (M_RELOAD_N, active low), and power switch control (POWER_KEY_N, active low) signals are connected to S32K148's PTD3, PTD2, and PTD4, respectively. As this module's core operating voltage is 3.3V, all connected communication and control signals pass through level-shifting chips.

Additionally, indicator LEDs for the 3G/4G communication module's operation are connected to the board's LEDs.

3.9 Three-Axis Accelerometer and RTC Real-Time Clock Module Circuit

The MM8452Q three-axis accelerometer, used for detecting vehicle attitude, and the PCA85063 RTC real-time clock chip, used for precise timing, are both connected to the S32K148's LPI2C1 (PTD19/PTC31). Their respective interrupt signals are connected to the S32K148's PTD22 and PTD23. Since both modules operate at 3.3V, all interconnected S32K148 ports pass through level-shifting chips.

According to the hardware design, the I2C slave addresses for the three-axis accelerometer and the RTC real-time clock chip are 0x1C and 0x51, respectively.

Alternatively, users can opt to use the S32K148's internal RTC real-time clock module. For this purpose, a 32.768 KHz crystal oscillator has been designed as its RTC reference clock. Its operating voltage supports both 3.3V and 5V, selectable via jumper J34. By default, J34 pins 1 and 2 are shorted, selecting VDD_MCU as its power source. The S32K148's PTA6 is also used for clock enable control (CLKOE, active high).

3.10 Audio Codec Circuit

The SGTL5000 is used as the audio codec in this design, communicating with the S32K148's SAI0 module via the I2S interface (PTA10/PTA11/PTA12/PTA13). During initialization, the S32K148's LPI2C0 (PTA2/PTA3) is used for parameter configuration.

Audio input sources include the microphone at P1, LINE IN at J14, and I2S data from the S32K148. Audio outputs include LINE OUT at J15 and headphone output at J16. The microphone's captured audio data or LINE IN input audio data can also be sent to the S32K148 for processing via the I2S interface.

3.11 User Buttons, RGB LED, Touch Sensing Inputs, etc.

The circuit design for the two user buttons is as follows: they are connected to the S32K148's PTC12 and PTC13. Pressing the buttons outputs a high level.

The RGB three-color LED circuit is connected as follows: the control pins for the red, green, and blue LEDs are connected to the S32K148's PTE21, PTE22, and PTE23, respectively. A high level turns the LEDs off, and a low level turns them on.

Two capacitive touch sensor electrodes are connected to ADCO (ADCO_SEO/ADCO_SE1) and PTA (PTAO/PTA1/PTA15/PTA16), which can be used for user input.

Additionally, to evaluate the ADC module, a sliding potentiometer is connected to ADCO_SE28 (PTC28) or ADC1_SE15 (PTB16). This selection can be made via jumper R124 and R117. By default, R124 is soldered and R117 is DNP, so the sliding potentiometer's output is connected to ADCO_SE28.

3.12 23-pin ECU Connector Circuit (PWM_IN/HS_OUT/EXT_ECU_ADC_IN)

Provides 2 external PWM input channels, connected to the S32K148's FTM6_CH0 (PTB20) and FTM6_CH1 (PTB21).

Provides 2 high-side output channels, connected to the S32K148's FTM7_CH1 (PTD28) and FTM7_CH3 (PTD30).

Provides 2 external analog signal input channels, connected to the S32K148's ADC0_SE6 (PTB2) and ADC0_SE7 (PTB3).

All external ECU communication and control input/output signals are connected to a 23-PIN dedicated ECU connector—J31, for user convenience.

Shorting J32 and J33 enables LIN1 and LIN2 to be used as master nodes.

Considering the external connections of the ECU connector, to enhance the system's ESD and EMC characteristics, a 0.100 pF capacitor is added to each signal pin of the connector, but it is DNP by default. Users can decide whether to solder it based on their needs.

For detailed circuit information, please refer to SPF-32232.pdf (Rev B).

4. MCU Pin Definitions and 23-PIN ECU Connector Wiring Harness

4.1 S32K148 Pin Allocation

Please open the PDF attachment of this document, S32K148 base T-Box_GP-ECU pin allocation.xlsx, to view the pin allocation.

4.2 23-PIN ECU Connector Pin Definitions

The manufactured wiring harness is shown in the figure below.

5. Appendix - Reference Documents

1. AN5426, Hardware Design Guidelines for S32K1xx Microcontrollers (REV 2), https://www.nxp.com/S32K
2. S32K1xx MCU Family Data Sheet (REV 9), https://www.nxp.com/S32K
3. S32K1xx MCU Family Reference Manual (REV 9), https://www.nxp.com/S32K