SPRSP35K February   2019  – April 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
    1. 3.1 Functional Block Diagram
  5. 4 Device Comparison
    1. 4.1 Related Products
  6. 5 Terminal Configuration and Functions
    1. 5.1 Pin Diagram
    2. 5.2 Pin Attributes
    3. 5.3 Signal Descriptions
      1. 5.3.1  ADC
        1. 5.3.1.1 MCU Domain
      2. 5.3.2  DDRSS
        1. 5.3.2.1 MAIN Domain
      3. 5.3.3  GPIO
        1. 5.3.3.1 MAIN Domain
        2. 5.3.3.2 WKUP Domain
      4. 5.3.4  I2C
        1. 5.3.4.1 MAIN Domain
        2. 5.3.4.2 MCU Domain
        3. 5.3.4.3 WKUP Domain
      5. 5.3.5  I3C
        1. 5.3.5.1 MAIN Domain
        2. 5.3.5.2 MCU Domain
      6. 5.3.6  MCAN
        1. 5.3.6.1 MAIN Domain
        2. 5.3.6.2 MCU Domain
      7. 5.3.7  MCSPI
        1. 5.3.7.1 MAIN Domain
        2. 5.3.7.2 MCU Domain
      8. 5.3.8  UART
        1. 5.3.8.1 MAIN Domain
        2. 5.3.8.2 MCU Domain
        3. 5.3.8.3 WKUP Domain
      9. 5.3.9  MDIO
        1. 5.3.9.1 MCU Domain
      10. 5.3.10 CPSW2G
        1. 5.3.10.1 MCU Domain
      11. 5.3.11 CPSW9G
        1. 5.3.11.1 MAIN Domain
      12. 5.3.12 ECAP
        1. 5.3.12.1 MAIN Domain
      13. 5.3.13 EQEP
        1. 5.3.13.1 MAIN Domain
      14. 5.3.14 EHRPWM
        1. 5.3.14.1 MAIN Domain
      15. 5.3.15 USB
        1. 5.3.15.1 MAIN Domain
      16. 5.3.16 SERDES
        1. 5.3.16.1 MAIN Domain
      17. 5.3.17 OSPI
        1. 5.3.17.1 MCU Domain
      18. 5.3.18 Hyperbus
        1. 5.3.18.1 MCU Domain
      19. 5.3.19 GPMC
        1. 5.3.19.1 MAIN Domain
      20. 5.3.20 MMC
        1. 5.3.20.1 MAIN Domain
      21. 5.3.21 CPTS
        1. 5.3.21.1 MCU Domain
        2. 5.3.21.2 MAIN Domain
      22. 5.3.22 UFS
        1. 5.3.22.1 MAIN Domain
      23. 5.3.23 PRU_ICSSG [Currently Not Supported]
        1. 5.3.23.1 MAIN Domain
      24. 5.3.24 MCASP
        1. 5.3.24.1 MAIN Domain
      25. 5.3.25 DSS
        1. 5.3.25.1 MAIN Domain
      26. 5.3.26 DP
        1. 5.3.26.1 MAIN Domain
      27. 5.3.27 Camera Streaming Interface Receiver (CSI_RX_IF) Subsystem
        1. 5.3.27.1 MAIN Domain
      28. 5.3.28 DSI_TX
        1. 5.3.28.1 MAIN Domain
      29. 5.3.29 VPFE
        1. 5.3.29.1 MAIN Domain
      30. 5.3.30 DMTIMER
        1. 5.3.30.1 MAIN Domain
        2. 5.3.30.2 MCU Domain
      31. 5.3.31 Emulation and Debug
        1. 5.3.31.1 MAIN Domain
      32. 5.3.32 System and Miscellaneous
        1. 5.3.32.1 Boot Mode Configuration
          1. 5.3.32.1.1 MAIN Domain
          2. 5.3.32.1.2 MCU Domain
        2. 5.3.32.2 Clock
          1. 5.3.32.2.1 MAIN Domain
          2. 5.3.32.2.2 WKUP Domain
        3. 5.3.32.3 System
          1. 5.3.32.3.1 MAIN Domain
          2. 5.3.32.3.2 WKUP Domain
        4. 5.3.32.4 EFUSE
      33. 5.3.33 Power Supply
    4. 5.4 Pin Multiplexing
    5. 5.5 Pin Connectivity Requirements
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Power-On-Hour (POH) Limits
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Operating Performance Points
    6. 6.6 Electrical Characteristics
      1. 6.6.1  I2C, Open-Drain, Fail-Safe (I2C OD FS) Electrical Characteristics
      2. 6.6.2  Fail-Safe Reset (FS Reset) Electrical Characteristics
      3. 6.6.3  HFOSC/LFOSC Electrical Characteristics
      4. 6.6.4  eMMCPHY Electrical Characteristics
      5. 6.6.5  SDIO Electrical Characteristics
      6. 6.6.6  CSI-2/DSI D-PHY Electrical Characteristics
      7. 6.6.7  ADC12B Electrical Characteristics
      8. 6.6.8  MLB LVCMOS Electrical Characteristics
      9. 6.6.9  LVCMOS Electrical Characteristics
      10. 6.6.10 USB2PHY Electrical Characteristics
      11. 6.6.11 SerDes 4-L-PHY/2-L-PHY Electrical Characteristics
      12. 6.6.12 UFS M-PHY Electrical Characteristics
      13. 6.6.13 eDP/DP AUX-PHY Electrical Characteristics
      14. 6.6.14 DDR0 Electrical Characteristics
    7. 6.7 VPP Specifications for One-Time Programmable (OTP) eFuses
      1. 6.7.1 Recommended Operating Conditions for OTP eFuse Programming
      2. 6.7.2 Hardware Requirements
      3. 6.7.3 Programming Sequence
      4. 6.7.4 Impact to Your Hardware Warranty
    8. 6.8 Thermal Resistance Characteristics
      1. 6.8.1 Thermal Resistance Characteristics for ALF Package
    9. 6.9 Timing and Switching Characteristics
      1. 6.9.1 Timing Parameters and Information
      2. 6.9.2 Power Supply Sequencing
        1. 6.9.2.1 Power Supply Slew Rate Requirement
        2. 6.9.2.2 Combined MCU and Main Domains Power-Up Sequencing
        3. 6.9.2.3 Combined MCU and Main Domains Power- Down Sequencing
        4. 6.9.2.4 Isolated MCU and Main Domains Power- Up Sequencing
        5. 6.9.2.5 Isolated MCU and Main Domains, Primary Power- Down Sequencing
        6. 6.9.2.6 Entry and Exit of MCU Only State
        7. 6.9.2.7 Entry and Exit of DDR Retention State
      3. 6.9.3 System Timing
        1. 6.9.3.1 Reset Timing
        2. 6.9.3.2 Safety Signal Timing
        3. 6.9.3.3 Clock Timing
      4. 6.9.4 Clock Specifications
        1. 6.9.4.1 Input and Output Clocks / Oscillators
          1. 6.9.4.1.1 WKUP_OSC0 Internal Oscillator Clock Source
            1. 6.9.4.1.1.1 Load Capacitance
            2. 6.9.4.1.1.2 Shunt Capacitance
          2. 6.9.4.1.2 WKUP_OSC0 LVCMOS Digital Clock Source
          3. 6.9.4.1.3 Auxiliary OSC1 Internal Oscillator Clock Source
            1. 6.9.4.1.3.1 Load Capacitance
            2. 6.9.4.1.3.2 Shunt Capacitance
          4. 6.9.4.1.4 Auxiliary OSC1 LVCMOS Digital Clock Source
          5. 6.9.4.1.5 Auxiliary OSC1 Not Used
          6. 6.9.4.1.6 WKUP_LFOSC0 Internal Oscillator Clock Source
            1. 6.9.4.1.6.1 WKUP_LFOSC0 Not Used
        2. 6.9.4.2 Output Clocks
        3. 6.9.4.3 PLLs
        4. 6.9.4.4 Module and Peripheral Clocks Frequencies
      5. 6.9.5 Peripherals
        1. 6.9.5.1  ATL
          1. 6.9.5.1.1 ATL_PCLK Timing Requirements
          2. 6.9.5.1.2 ATL_AWS[x] Timing Requirements
          3. 6.9.5.1.3 ATL_BWS[x] Timing Requirements
          4. 6.9.5.1.4 ATCLK[x] Switching Characteristics
        2. 6.9.5.2  VPFE
        3. 6.9.5.3  CPSW2G
          1. 6.9.5.3.1 CPSW2G MDIO Interface Timings
          2. 6.9.5.3.2 CPSW2G RMII Timings
            1. 6.9.5.3.2.1 CPSW2G RMII[x]_REF_CLK Timing Requirements – RMII Mode
            2. 6.9.5.3.2.2 CPSW2G RMII[x]_RXD[1:0], RMII[x]_CRS_DV, and RMII[x]_RX_ER Timing Requirements – RMII Mode
            3. 6.9.5.3.2.3 CPSW2G RMII[x]_TXD[1:0], and RMII[x]_TX_EN Switching Characteristics – RMII Mode
          3. 6.9.5.3.3 CPSW2G RGMII Timings
            1. 6.9.5.3.3.1 RGMII[x]_RXC Timing Requirements – RGMII Mode
            2. 6.9.5.3.3.2 CPSW2G Timing Requirements for RGMII[x]_RD[3:0], and RGMII[x]_RCTL – RGMII Mode
            3. 6.9.5.3.3.3 CPSW2G RGMII[x]_TXC Switching Characteristics – RGMII Mode
            4. 6.9.5.3.3.4 RGMII[x]_TD[3:0], and RGMII[x]_TX_CTL Switching Characteristics – RGMII Mode
        4. 6.9.5.4  CPSW9G
          1. 6.9.5.4.1 CPSW9G MDIO Interface Timings
          2. 6.9.5.4.2 CPSW9G RMII Timings
            1. 6.9.5.4.2.1 RMII[x]_REF_CLK Timing Requirements – RMII Mode
            2. 6.9.5.4.2.2 RMII[x]_RXD[1:0], RMII[x]_CRS_DV, and RMII[x]_RX_ER Timing Requirements – RMII Mode
            3. 6.9.5.4.2.3 RMII[x]_TXD[1:0], and RMII[x]_TXEN Switching Characteristics – RMII Mode
          3. 6.9.5.4.3 CPSW9G RGMII Timings
            1. 6.9.5.4.3.1 RGMII[x]_RXC Timing Requirements – RGMII Mode
            2. 6.9.5.4.3.2 RGMII[x]_RD[3:0] and RGMII[x]_RCTL Timing Requirements – RGMII Mode
            3. 6.9.5.4.3.3 RGMII[x]_TXC Switching Characteristics – RGMII Mode
            4. 6.9.5.4.3.4 RGMII[x]_TD[3:0] and RGMII[x]_TX_CTL Switching Characteristics – RGMII Mode
        5. 6.9.5.5  CSI-2
        6. 6.9.5.6  DDRSS
        7. 6.9.5.7  DSS
        8. 6.9.5.8  eCAP
          1. 6.9.5.8.1 Timing Requirements for eCAP
          2. 6.9.5.8.2 Switching Characteristics for eCAP
        9. 6.9.5.9  EPWM
          1. 6.9.5.9.1 Timing Requirements for eHRPWM
          2. 6.9.5.9.2 Switching Characteristics for eHRPWM
        10. 6.9.5.10 eQEP
          1. 6.9.5.10.1 Timing Requirements for eQEP
          2. 6.9.5.10.2 Switching Characteristics for eQEP
        11. 6.9.5.11 GPIO
          1. 6.9.5.11.1 GPIO Timing Requirements
          2. 6.9.5.11.2 GPIO Switching Characteristics
        12. 6.9.5.12 GPMC
          1. 6.9.5.12.1 GPMC and NOR Flash — Synchronous Mode
            1. 6.9.5.12.1.1 GPMC and NOR Flash Timing Requirements — Synchronous Mode
            2. 6.9.5.12.1.2 GPMC and NOR Flash Switching Characteristics – Synchronous Mode
          2. 6.9.5.12.2 GPMC and NOR Flash — Asynchronous Mode
            1. 6.9.5.12.2.1 GPMC and NOR Flash Timing Requirements – Asynchronous Mode
            2. 6.9.5.12.2.2 GPMC and NOR Flash Switching Characteristics – Asynchronous Mode
          3. 6.9.5.12.3 GPMC and NAND Flash — Asynchronous Mode
            1. 6.9.5.12.3.1 GPMC and NAND Flash Timing Requirements – Asynchronous Mode
            2. 6.9.5.12.3.2 GPMC and NAND Flash Switching Characteristics – Asynchronous Mode
          4. 6.9.5.12.4 GPMC0 IOSET
        13. 6.9.5.13 HyperBus
          1. 6.9.5.13.1 Timing Requirements for HyperBus
          2. 6.9.5.13.2 HyperBus 166 MHz Switching Characteristics
          3. 6.9.5.13.3 HyperBus 100 MHz Switching Characteristics
        14. 6.9.5.14 I2C
        15. 6.9.5.15 I3C
        16. 6.9.5.16 MCAN
        17. 6.9.5.17 MCASP
        18. 6.9.5.18 MCSPI
          1. 6.9.5.18.1 MCSPI — Master Mode
          2. 6.9.5.18.2 MCSPI — Slave Mode
        19. 6.9.5.19 MMCSD
          1. 6.9.5.19.1 MMC0 - eMMC Interface
            1. 6.9.5.19.1.1 Legacy SDR Mode
            2. 6.9.5.19.1.2 High Speed SDR Mode
            3. 6.9.5.19.1.3 High Speed DDR Mode
            4. 6.9.5.19.1.4 HS200 Mode
          2. 6.9.5.19.2 MMC1/2 - SD/SDIO Interface
            1. 6.9.5.19.2.1 Default Speed Mode
            2. 6.9.5.19.2.2 High Speed Mode
            3. 6.9.5.19.2.3 UHS–I SDR12 Mode
            4. 6.9.5.19.2.4 UHS–I SDR25 Mode
            5. 6.9.5.19.2.5 UHS–I SDR50 Mode
            6. 6.9.5.19.2.6 UHS–I DDR50 Mode
            7. 6.9.5.19.2.7 UHS–I SDR104 Mode
        20. 6.9.5.20 CPTS
          1. 6.9.5.20.1 CPTS Timing Requirements
          2. 6.9.5.20.2 CPTS Switching Characteristics
        21. 6.9.5.21 OSPI
          1. 6.9.5.21.1 OSPI PHY Mode
            1. 6.9.5.21.1.1 OSPI With Data Training
              1. 6.9.5.21.1.1.1 OSPI Switching Characteristics – Data Training
            2. 6.9.5.21.1.2 OSPI Without Data Training
              1. 6.9.5.21.1.2.1 OSPI Timing Requirements – SDR Mode
              2. 6.9.5.21.1.2.2 OSPI Switching Characteristics – SDR Mode
              3. 6.9.5.21.1.2.3 OSPI Timing Requirements – DDR Mode
              4. 6.9.5.21.1.2.4 OSPI Switching Characteristics – DDR Mode
          2. 6.9.5.21.2 OSPI Tap Mode
            1. 6.9.5.21.2.1 OSPI Tap SDR Timing
            2. 6.9.5.21.2.2 OSPI Tap DDR Timing
        22. 6.9.5.22 PCIE
        23. 6.9.5.23 Timers
          1. 6.9.5.23.1 Timing Requirements for Timers
          2. 6.9.5.23.2 Switching Characteristics for Timers
        24. 6.9.5.24 UART
          1. 6.9.5.24.1 Timing Requirements for UART
          2. 6.9.5.24.2 UART Switching Characteristics
        25. 6.9.5.25 USB
      6. 6.9.6 Emulation and Debug
        1. 6.9.6.1 Trace
        2. 6.9.6.2 JTAG
          1. 6.9.6.2.1 JTAG Electrical Data and Timing
            1. 6.9.6.2.1.1 JTAG Timing Requirements
            2. 6.9.6.2.1.2 JTAG Switching Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Processor Subsystems
      1. 7.2.1 Arm Cortex-A72
      2. 7.2.2 Arm Cortex-R5F
      3. 7.2.3 DSP C71x
      4. 7.2.4 DSP C66x
    3. 7.3 Accelerators and Coprocessors
      1. 7.3.1 GPU
      2. 7.3.2 D5520MP2
      3. 7.3.3 VXE384MP2
    4. 7.4 Other Subsystems
      1. 7.4.1 MSMC
      2. 7.4.2 NAVSS
        1. 7.4.2.1 NAVSS0
        2. 7.4.2.2 MCU_NAVSS
      3. 7.4.3 PDMA Controller
      4. 7.4.4 Power Supply
      5. 7.4.5 Peripherals
        1. 7.4.5.1  ADC
        2. 7.4.5.2  ATL
        3. 7.4.5.3  CSI
          1. 7.4.5.3.1 Camera Streaming Interface Receiver (CSI_RX_IF) and MIPI DPHY Receiver (DPHY_RX)
          2. 7.4.5.3.2 Camera Streaming Interface Transmitter (CSI_TX_IF)
        4. 7.4.5.4  CPSW2G
        5. 7.4.5.5  CPSW9G
        6. 7.4.5.6  DCC
        7. 7.4.5.7  DDRSS
        8. 7.4.5.8  DSS
          1. 7.4.5.8.1 DSI
          2. 7.4.5.8.2 eDP
        9. 7.4.5.9  VPFE
        10. 7.4.5.10 eCAP
        11. 7.4.5.11 EPWM
        12. 7.4.5.12 ELM
        13. 7.4.5.13 ESM
        14. 7.4.5.14 eQEP
        15. 7.4.5.15 GPIO
        16. 7.4.5.16 GPMC
        17. 7.4.5.17 Hyperbus
        18. 7.4.5.18 I2C
        19. 7.4.5.19 I3C
        20. 7.4.5.20 MCAN
        21. 7.4.5.21 MCASP
        22. 7.4.5.22 MCRC Controller
        23. 7.4.5.23 MCSPI
        24. 7.4.5.24 MMC/SD
        25. 7.4.5.25 OSPI
        26. 7.4.5.26 PCIE
        27. 7.4.5.27 SerDes
        28. 7.4.5.28 WWDT
        29. 7.4.5.29 Timers
        30. 7.4.5.30 UART
        31. 7.4.5.31 USB
        32. 7.4.5.32 UFS
  9. 8 Applications and Implementation
    1. 8.1 Power Supply Mapping
    2. 8.2 Device Connection and Layout Fundamentals
      1. 8.2.1 Power Supply Decoupling and Bulk Capacitors
        1. 8.2.1.1 Power Distribution Network Implementation Guidance
      2. 8.2.2 External Oscillator
      3. 8.2.3 JTAG and EMU
      4. 8.2.4 Reset
      5. 8.2.5 Unused Pins
      6. 8.2.6 Hardware Design Guide for JacintoTM 7 Devices
    3. 8.3 Peripheral- and Interface-Specific Design Information
      1. 8.3.1 LPDDR4 Board Design and Layout Guidelines
      2. 8.3.2 OSPI and QSPI Board Design and Layout Guidelines
        1. 8.3.2.1 No Loopback and Internal Pad Loopback
        2. 8.3.2.2 External Board Loopback
        3. 8.3.2.3 DQS (only available in Octal Flash devices)
      3. 8.3.3 SERDES REFCLK Design Guidelines
      4. 8.3.4 USB VBUS Design Guidelines
      5. 8.3.5 System Power Supply Monitor Design Guidelines
      6. 8.3.6 High Speed Differential Signal Routing Guidance
      7. 8.3.7 Thermal Solution Guidance
  10. 9 Device and Documentation Support
    1. 9.1 Device Nomenclature
      1. 9.1.1 Standard Package Symbolization
      2. 9.1.2 Device Naming Convention
    2. 9.2 Tools and Software
    3. 9.3 Documentation Support
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Packaging Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • ALF|827
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5.5 Pin Connectivity Requirements

This section describes the Unused/Reserved balls connection requirements.

Note:

All power balls must be supplied with the voltages specified in Section 6.4, Recommended Operating Conditions, unless otherwise specified in Section 5.3, Signal Descriptions.

Note:

MMC1_SDCD and MMC2_SDCD must be pulled down for respective MMC modules to work properly as a boot source.

Table 5-126 Connectivity Requirements (ALF Package)
BALL NUMBER BALL NAME CONNECTION REQUIREMENTS
M29 WKUP_OSC0_XI Each of these balls must be connected to VSS through a separate external pull resistor to ensure these balls are held to a valid logic low level if unused.
P29 OSC1_XI
N28 WKUP_LFOSC0_XI
F24 TRSTn
K25 MCU_ADC0_AIN0
K26 MCU_ADC0_AIN1
K28 MCU_ADC0_AIN2
L28 MCU_ADC0_AIN3
K24 MCU_ADC0_AIN4
K27 MCU_ADC0_AIN5
K29 MCU_ADC0_AIN6
L29 MCU_ADC0_AIN7
N23 MCU_ADC1_AIN0
M25 MCU_ADC1_AIN1
L24 MCU_ADC1_AIN2
L26 MCU_ADC1_AIN3
N24 MCU_ADC1_AIN4
M24 MCU_ADC1_AIN5
L25 MCU_ADC1_AIN6
L27 MCU_ADC1_AIN7
B2 DDR0_DQS0P
E3 DDR0_DQS1P
M3 DDR0_DQS2P
R2 DDR0_DQS3P
M26 VMON_ER_VSYS
V19 VMON_IR_VEXT
AE18 SERDES0_REXT Each of these balls must be connected to VSS through appropriate external pull resistor to ensure these balls are held to a valid logic low level if unused. The resistor value for the SERDES[4:0]_REXT pins is 3.01 kΩ ±1%, for the CSI[1:0]_RXRCALIB, USB[1:0]_RCALIB, and DSI_TXRCALIB pins is 500 Ω ±1%. This is the same connection as during functional mode.
AE13 SERDES1_REXT
AD13 SERDES2_REXT
AE8 SERDES3_REXT
F9 SERDES4_REXT
F16 CSI0_RXRCALIB
F15 CSI1_RXRCALIB
AB6 USB0_RCALIB
AD9 USB1_RCALIB
F12 DSI_TXRCALIB
D28 MCU_RESETz Each of these balls must be connected to the corresponding power supply through a separate external pull resistor to ensure these balls are held to a valid logic high level if unused.(1)
H23 MCU_PORz
J24 PORz
E29 TCK
V2 TMS
J25 WKUP_I2C0_SCL
H24 WKUP_I20_SDA
H25 MCU_I2C0_SDA
J26 MCU_I2C0_SCL
Y6 I2C1_SCL
AA6 I2C1_SDA
AA5 I2C0_SDA
AC5 I2C0_SCL
AC18 EXTINTn
V1 TDI
V3 TDO
B29 EMU1
C26 EMU0
B1 DDR0_DQS0N
E2 DDR0_DQS1N
M2 DDR0_DQS2N
R1 DDR0_DQS3N
AB11 VPP_CORE Each of these balls must be left unconnected if unused.
F17 VPP_MCU
AE1 MMC0_CALPAD
AE2 MLB0_MLBCN
AD2 MLB0_MLBCP
AD3 MLB0_MLBDN
AC3 MLB0_MLBDP
AC1 MLB0_MLBSN
AD1 MLB0_MLBSP
(1) To determine which power supply is associated with any IO refer to Table 5-1, Pin Attributes.

Table 5-127 Reserved Balls Specific Connection Requirements
BALLS CONNECTION REQUIREMENTS
A29 / AJ1 / U11 / U12 / U13 / T11 / T12 / T13 / M11 / M12 / M13 / N11 / N12 / N13 These balls do not exist on the package.
N25 / AJ29 / P26 / R27 / AD4 / E18 / F18 / G10 / F11 / N6 / L6 / F6 / E6 / G9 / F10 / AA23 / F13 These balls must be left unconnected.
Note:

All other unused signal balls without Pad Configuration Register can be left unconnected.

Note:

All other unused signal balls with a Pad Configuration Register can be left unconnected with their multiplexing mode set to GPIO input and internal pulldown resistor enabled.

Unused balls are defined as those which only connect to a PCB solder pad. This is the only use case where internal pull resistors are allowed as the only source/sink to hold a valid logic level.

Any balls connected to a via, test point, or PCB trace are considered used and must not depend on the internal pull resistor to hold a valid logic level.

Internal pull resistors are weak and may not source enough current to maintain a valid logic level for some operating conditions. This may be the case when connected to components with leakage to the opposite logic level, or when external noise sources couple to signal traces attached to balls which are only pulled to a valid logic level by the internal resistor. Therefore, external pull resistors may be required to hold a valid logic level on balls with external connections.

If balls are allowed to float between valid logic levels, the input buffer may enter a high-current state which could damage the IO cell.