SLVUCU5 December   2025 UCD91160 , UCD91320

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. Power Supply Sequencing
    1. 1.1 Overview
    2. 1.2 Rail On and Off Configuration
    3. 1.3 Rail Power Good
    4. 1.4 Rail Sequence Configuration
    5. 1.5 Rail States
    6. 1.6 Rail Sequencing Example Use Cases
  5. GPIOs
    1. 2.1 Overview
    2. 2.2 Command Controlled GPOs
    3. 2.3 Logic GPOs
      1. 2.3.1 Boolean Logic Builder
    4. 2.4 GPIs
      1. 2.4.1 GPI Special Functionality
      2. 2.4.2 GPI Fault Responses
      3. 2.4.3 GPI Latched Status Clearing
      4. 2.4.4 GPI Debug Pin
      5. 2.4.5 GPI Fault Pin
    5. 2.5 Power Supply Enable Pins
    6. 2.6 Cascading Pins
    7. 2.7 Margining Pins
  6. GPI State Machine
    1. 3.1 Overview
    2. 3.2 GPI State Machine Configuration
  7. Monitoring
  8. Rail Profiles
  9. Margining
    1. 6.1 Overview
    2. 6.2 Operation
    3. 6.3 Idle Behavior of Margining Pins
  10. Cascading
    1. 7.1 Overview
    2. 7.2 Power On Cascading
    3. 7.3 Power On and Off Cascading
    4. 7.4 Fault Cascading
    5. 7.5 Cascading Requirements
  11. Fault Handling
  12. Fault Logging
  13. 10Memory
    1. 10.1 Overview
    2. 10.2 Flash Memory
    3. 10.3 Power Up
    4. 10.4 Program Lifetime
  14. 11Internal Fault Management
  15. 12Status Monitoring
  16. 13Device Reset
  17. 14ADC Reference
  18. 15System Watchdog
  19. 16System Reset
  20. 17PMBus Specification
    1. 17.1 Manufacturer Specific Status (STATUS_MFR_SPECIFIC)
  21. 18Data Formats
    1. 18.1 Data Format for Output Voltage Parameters
    2. 18.2 Data Format for Other Parameters
    3. 18.3 Distinguishing Between Linear Data Formats
    4. 18.4 Translation, Quantization, and Truncation
    5. 18.5 8-Bit Time Encoding
    6. 18.6 16-Bit Time Encoding
  22. 19Memory Model
  23. 20Alert Response Address Support
  24. 21Supported PMBus Commands
  25. 22Implementation Details for PMBus Core Commands
    1. 22.1  (00h) PAGE
    2. 22.2  (01h) OPERATION
    3. 22.3  (0Eh) PASSKEY
    4. 22.4  (0Fh) ACCESS_CONTROL
    5. 22.5  (11h) STORE_DEFAULT_ALL
    6. 22.6  (12h) RESTORE_DEFAULT_ALL
    7. 22.7  (1Bh) SMBALERT_MASK
    8. 22.8  (20h) VOUT_MODE
    9. 22.9  (38h) IOUT_CAL_GAIN
    10. 22.10 (41h – 69h) xxx_FAULT_RESPONSE
    11. 22.11 (62h) TON_MAX_FAULT_LIMIT
    12. 22.12 (66h) TOFF_MAX_WARN_LIMIT
    13. 22.13 (80h) STATUS_MFR_SPECIFIC
    14. 22.14 (8Dh) READ_TEMPERATURE_1
    15. 22.15 (8Eh) READ_TEMPERATURE_2
    16. 22.16 (ADh) IC_DEVICE_ID
    17. 22.17 (AEh) IC_DEVICE_REV
  26. 23Input and Output Pin Configuration
  27. 24PWM Configuration
  28. 25Implementation Details for User Data Commands
    1. 25.1 (B5h) FIRST_BLACK_BOX_FAULT_INFO (USER_DATA_05)
    2. 25.2 (B6h) LAST_BLACK_BOX_FAULT_INFO Command Format(USER_DATA_06)
    3. 25.3 (B8h) RAIL_PROFILE (USER_DATA_08)
      1. 25.3.1 Number Profile
      2. 25.3.2 Profile Index
    4. 25.4 (B9h) RAIL_STATE (USER_DATA_09)
  29. 26Implementation Details for Manufacturer-Specific Commands
    1. 26.1  Manufacturer-Specific Commands Notice
    2. 26.2  (D0h) FAULT_PIN_CONFIG (MFR_SPECIFIC_00)
      1. 26.2.1 Fault Pin Configuration
      2. 26.2.2 Page Mask
      3. 26.2.3 GPI Mask
      4. 26.2.4 Other Mask
    3. 26.3  (D1h) VOUT_CAL_MONITOR (MFR_SPECIFIC_01)
    4. 26.4  (D2h) SYSTEM_RESET_CONFIG (MFR_SPECIFIC_02)
      1. 26.4.1 GPI Flags
      2. 26.4.2 Page Flags
      3. 26.4.3 Deassert When Power-Good
      4. 26.4.4 Assert When NOT Power-Good
      5. 26.4.5 Assert When Watchdog Timeout
      6. 26.4.6 Delay Time
      7. 26.4.7 Pulse Time
      8. 26.4.8 GPI Tracking
      9. 26.4.9 Reset Pin Configuration
    5. 26.5  (D3h) SYSTEM_WATCHDOG_CONFIG (MFR_SPECIFIC_03)
      1. 26.5.1 Enable
      2. 26.5.2 Watch Reset Pin
      3. 26.5.3 Disable Until System Reset Release
      4. 26.5.4 Start Time
      5. 26.5.5 Input Pin (WDI) Configuration
      6. 26.5.6 Reset Period
      7. 26.5.7 Output Pin (WDO) Configuration
    6. 26.6  (D4h) SYSTEM_WATCHDOG_RESET (MFR_SPECIFIC_04)
    7. 26.7  (D5h) MONITOR_CONFIG (MFR_SPECIFIC_05)
    8. 26.8  (D6h) NUM_PAGES (MFR_SPECIFIC_06)
    9. 26.9  (D7h) RUN_TIME_CLOCK (MFR_SPECIFIC_07)
    10. 26.10 (D8h) RUN_TIME_CLOCK_TRIM (MFR_SPECIFIC_08)
    11. 26.11 (DAh) USER_RAM_00 (MFR_SPECIFIC_10)
    12. 26.12 (DBh) SOFT_RESET (MFR_SPECIFIC_11)
    13. 26.13 (DCh) RESET_COUNT (MFR_SPECIFIC_12)
    14. 26.14 (DDh) PIN_SELECTED_RAIL_STATES (MFR_SPECIFIC_13)
      1. 26.14.1 System State Enables
      2. 26.14.2 Soft Off Enables
      3. 26.14.3 System State
    15. 26.15 (DEh) RESEQUENCE (MFR_SPECIFIC_14)
    16. 26.16 (DFh) CONSTANTS (MFR_SPECIFIC_15)
    17. 26.17 (E0h) PWM_SELECT (MFR_SPECIFIC_16)
    18. 26.18 (E1h) PWM_CONFIG (MFR_SPECIFIC_17)
    19. 26.19 (E2h) PARM_INFO (MFR_SPECIFIC_18)
    20. 26.20 (E3h) PARM_VALUE (MFR_SPECIFIC_19)
    21. 26.21 (E4h) TEMPERATURE_CAL_GAIN (MFR_SPECIFIC_20)
    22. 26.22 (E5h) TEMPERATURE_CAL_OFFSET (MFR_SPECIFIC_21)
    23. 26.23 (E6h) SET_BREAKPOINTS (MFR_SPECIFIC 22)
    24. 26.24 (E7h) DEBUG_CONTINUE (MFR_SPECIFIC_23)
    25. 26.25 (E9h) FAULT_RESPONSES (MFR_SPECIFIC_25)
      1. 26.25.1 Fault Response Bytes
      2. 26.25.2 Re-Sequence
      3. 26.25.3 Time Between Retries
      4. 26.25.4 Maximum Glitch Time for Voltage Faults
      5. 26.25.5 Maximum Glitch Time for Non-Voltage Faults
    26. 26.26 (EAh) LOGGED_FAULTS (MFR_SPECIFIC_26)
      1. 26.26.1 Command Format
      2. 26.26.2 Non-Paged Faults
      3. 26.26.3 GPI Faults
      4. 26.26.4 Page-Dependent Faults
    27. 26.27 (EBh) LOGGED_FAULT_DETAIL_INDEX (MFR_SPECIFIC_27)
    28. 26.28 (ECh) LOGGED_FAULT_DETAIL (MFR_SPECIFIC_28)
    29. 26.29 (EFh) LOG_FAULT_DETAIL_ENABLES (MFR_SPECIFIC_31)
    30. 26.30 (F0h) EXECUTE_FLASH (MFR_SPECIFIC_32)
    31. 26.31 (F1h) SECURITY (MFR_SPECIFIC_33)
    32. 26.32 F2h) SECURITY_BIT_MASK (MFR_SPECIFIC_34)
    33. 26.33 (F3h) MFR_STATUS (MFR_SPECIFIC_35)
    34. 26.34 (F4h) GPI_FAULT_RESPONSES (MFR_SPECIFIC_36)
      1. 26.34.1 Fault Responses Byte
      2. 26.34.2 Time Between Retries
      3. 26.34.3 Maximum Glitch Time for GPI
      4. 26.34.4 GPI Number Rail Profile Pin Selection
      5. 26.34.5 Block Out Period for Profile
    35. 26.35 (F5h) MARGIN_CONFIG (MFR_SPECIFIC_37)
    36. 26.36 (F6h) SEQ_CONFIG (MFR_SPECIFIC_38)
      1. 26.36.1  Enable Pin Configuration
      2. 26.36.2  GPI Sequence On Dependency Mask
      3. 26.36.3  GPI Sequence Off Dependency Mask
      4. 26.36.4  Sequencing Timeout Configuration
      5. 26.36.5  Sequencing On Timeout
      6. 26.36.6  Sequencing Off Timeout
      7. 26.36.7  Page Sequence On Dependency Mask
      8. 26.36.8  Page Sequence Off Dependency Mask
      9. 26.36.9  Fault Slaves Mask
      10. 26.36.10 GPO Sequence On Dependency Mask
      11. 26.36.11 GPO Sequence Off Dependency Mask
    37. 26.37 (F7h) GPO_CONFIG_INDEX (MFR_SPECIFIC_39)
    38. 26.38 (F8h) GPO_CONFIG (MFR_SPECIFIC_40)
      1. 26.38.1  Output Pin Configuration
      2. 26.38.2  Assert Delay Enable
      3. 26.38.3  Deassert Delay Enable
      4. 26.38.4  Invert OR Output
      5. 26.38.5  Ignore Inputs During Delay
      6. 26.38.6  Invert AND Output
      7. 26.38.7  State Machine Mode Enable
      8. 26.38.8  High Resolution Delay Count
      9. 26.38.9  Millisecond Delay
      10. 26.38.10 Status Mask
      11. 26.38.11 Status Inversion Mask
      12. 26.38.12 GPI Mask
      13. 26.38.13 GPI Inversion Mask
      14. 26.38.14 GPO Mask
      15. 26.38.15 GPO Inversion Mask
      16. 26.38.16 Status Type Select
      17. 26.38.17 GPO Configuration Examples
    39. 26.39 (F9h) GPI_CONFIG (MFR_SPECIFIC_41)
      1. 26.39.1 GPI Pin Configuration
      2. 26.39.2 Fault Enable Flags
      3. 26.39.3 Latched Statuses Clear Pin Selection
      4. 26.39.4 MRG_EN Pin Selection
      5. 26.39.5 MRG_LOW_nHIGH Pin Selection
      6. 26.39.6 Maximum Glitch Time for Fault Pin
      7. 26.39.7 GPI Debug Mode Pin Selection
    40. 26.40 (FAh) GPIO_SELECT (MFR_SPECIFIC_42)
    41. 26.41 (FBh) GPIO_CONFIG (MFR_SPECIFIC_43)
    42. 26.42 (FCh) MISC_CONFIG (MFR_SPECIFIC_44)
      1. 26.42.1 Miscellaneous Configuration Byte
      2. 26.42.2 Time Between Resequences
      3. 26.42.3 External Reference Voltage
      4. 26.42.4 Resequence_rails_mask
    43. 26.43 (FDh) DEVICE_ID (MFR_SPECIFIC_45)
  30. 27Range Checking and Limits
  31. 28Glossary
  32. 29Revision History

(ECh) LOGGED_FAULT_DETAIL (MFR_SPECIFIC_28)

This read-only command returns detail information about a given fault:

  1. The time that it happened in calendar formatted time (see Section 26.9)
  2. Whether or not the fault is page specific
  3. The page that the fault occurred on (when applicable)
  4. The type of fault (see Section 26.26)
Table 26-29 LOGGED_FAULT_DETAIL Command Format
Byte Number
(Read)
Payload IndexDescription
CMD = EC
0BYTE_COUNT = 12
10Seconds & Miliseconds (Low Byte)
21Seconds & Miliseconds (High Byte)
32Days, Hours, & Minutes (Low Byte)
43Days, Hours, & Minutes (High Byte)
54Year & Month (Low Byte)
65Year & Month (High Byte)
76Page Number
87Fault ID
98Fault Value (low byte)
109Fault Value (middle byte)

11

10

Fault Value (middle high byte)(1)
1211Fault Value (high byte)(1)
This byte is valid only if the current fault type is either Sequence On Timeout or Sequence Off Timeout.

New LOGGED_FAULT_DETAIL entries for a given fault are logged once and then not logged again until one of the following events occurs:

  1. Firmware is restarted.
  2. The rail stays in regulation for the amount of time determined by TON_MAX_FAULT_LIMIT. If TON_MAX_FAULT_LIMIT is set to 0, 4 seconds are used for the time. (This applies to paged faults only)
  3. The rail is turned off and then turned back on. (This applies to paged faults only.)
  4. The CLEAR_FAULTS command is written.
  5. The LOGGED_FAULTS command is written.

For temperature only rails, meaning rails with only a temperature monitor and no Enable pin assigned, an overtemperature fault will be logged once only, unless operating from a stored configuration.

The GPI fault is logged each time when the GPI state is changed to deasserted.

The maximum number of entries per device is show in Table 26-30. Once the maximum entries have been logged, no more detail is logged until the fault log is cleared (see Section 26.26). Unless, the “Enable Log FIFO” bit in the MISC_CONFIG command is set (see Table 26-46).

Table 26-30 Number of Log Entries in Each Device Type
DeviceEntries
UCD91160

100

UCD91320100

The fault identification byte indicates the type of fault, and whether or not that fault is page specific, see Table 26-36.

Table 26-31 Fault Identification
BitsDescription
7Page Specific (1 – yes, 0 – no)
6:0Fault Type

Information on the Fault Value (units and formatting) is shown inTable 26-32.

Table 26-32 Fault Value
Fault Type NumberPaged?DescriptionFault Value UnitsData Format
0NoReserved
1NoSystem Watchdog TimeoutNot Validn/a
2NoRe-sequence Error(3)Not Validn/a
3NoWatchdog TimeoutNot Validn/a
4NoSingle Event Upset (SEU)

n/a

5NoReserved

n/a

6NoReservedn/a
7NoReservedn/a
8No

Reserved

n/a
9NoGPI Fault(1)Not Validn/a
0YesVOUT_OV FaultVoltageLINEAR16
1YesVOUT_UV FaultVoltageLINEAR16
2YesTON_MAX FaultVoltageLINEAR16
3Yes

Reserved

n/a
4YesReservedn/a
5YesTEMPERATURE_OT FaultTemperatureLINEAR11
6YesSequence On TimeoutN/ABit Mask(2)
7YesSequence Off TimeoutN/ABit Mask(2)
The Page Number is used to encode which GPI that the fault information applies to.
Any bit set to 1 corresponds to a page dependency that is not met. The GPI dependencies that are not met are ORed into the 32-bits. So, for example, if page dependencies 2 and 5 are not met and GPI W (bit 4) dependency is not met, the fault value is 0x00000034.

A fault value is reserved for resequencing errors, but they are not logged.