SLVUCU5 December   2025 UCD91160 , UCD91320

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 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. 2 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. 3 GPI State Machine
    1. 3.1 Overview
    2. 3.2 GPI State Machine Configuration
  7. 4 Monitoring
  8. 5 Rail Profiles
  9. 6 Margining
    1. 6.1 Overview
    2. 6.2 Operation
    3. 6.3 Idle Behavior of Margining Pins
  10. 7 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. 8 Fault Handling
  12. 9 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

27 Range Checking and Limits

Table 27-1 shows the numerical limits for all the supported PMBus commands.

Table 27-1 Range and Limits for PMBus Commands
Code
(hex)		CommandMinimumMaximumHardcoded
Default		Comments
0PAGE013 or 2550
1OPERATIONSee commentsSee comments0The seven meaningful values for this parameter are 0x00, 0x40, 0x80, 0x94, 0x98, 0x98, 0xA4 and 0xA8.
2ON_OFF_CONFIGSee commentsSee comments0>0x20 invalid, all others accepted
3CLEAR_FAULTSn/an/an/aWrite Only
4PHASENot Supported
05-0FReserved
10WRITE_PROTECTNot Supported
11STORE_DEFAULT_ALLn/an/an/aWrite Only
12RESTORE_DEFAULT_ALLn/an/an/aWrite Only
13STORE_DEFAULT_CODENot Supported
14RESTORE_DEFAULT_CODENot Supported
15STORE_USER_ALLNot Supported
16RESTORE_USER_ALLNot Supported
17STORE_USER_CODENot Supported
18RESTORE_USER_CODENot Supported
19CAPABILITYn/an/a0xB0Read Only
1AQUERYNot Supported
1B-1FReserved
20VOUT_MODE–16150Five-bit, two’s complement exponent
21VOUT_COMMAND0See comment0Depends on VOUT_MODE
22VOUT_TRIMNot Supported
23VOUT_CAL_OFFSETNot Supported
24VOUT_MAXNot Supported
25VOUT_MARGIN_HIGH0See comment0Depends on VOUT_MODE
26VOUT_MARGIN_LOW0See comment0Depends on VOUT_MODE
27VOUT_TRANSITION_RATENot Supported
28VOUT_DROOPNot Supported
29VOUT_SCALE_LOOPNot Supported
2AVOUT_SCALE_MONITOR0See comment0Depends on VOUT_MODE
2B-2FReserved
30COEFFICIENTSNot Supported
31POUT_MAXNot Supported
32MAX_DUTYNot Supported
33FREQUENCY_SWITCHNot Supported
34Reserved
35VIN_ONNot Supported
36VIN_OFFNot Supported
37INTERLEAVENot Supported
38IOUT_CAL_GAIN0.6113200000A number from 20000 to 40031 results in 20000 because of internal resolution.
39IOUT_CAL_OFFSET–511.5511.50
3AFAN_CONFIG_1_2Not Supported
3BFAN_COMMAND_1Not Supported
3CFAN_COMMAND_2Not Supported
3DFAN_CONFIG_3_4Not Supported
3EFAN_COMMAND_3Not Supported
3FFAN_COMMAND_4Not Supported
40VOUT_OV_FAULT_LIMIT0See comment0Depends on VOUT_MODE
41VOUT_OV_FAULT_RESPONSESee FAULT_RESPONSES command
42VOUT_OV_WARN_LIMIT0See comment0Depends on VOUT_MODE
43VOUT_UV_WARN_LIMIT0See comment0Depends on VOUT_MODE
44VOUT_UV_FAULT_LIMIT0See comment0Depends on VOUT_MODE
45VOUT_UV_FAULT_RESPONSESee FAULT_RESPONSES command
46IOUT_OC_FAULT_LIMIT–511.5511.50
47IOUT_OC_FAULT_RESPONSESee FAULT_RESPONSES command
48IOUT_OC_LV_FAULT_LIMITNot Supported
49IOUT_OC_LV_FAULT_RESPONSENot Supported
4AIOUT_OC_WARN_LIMIT–511.5511.50
4BIOUT_UC_FAULT_LIMIT–511.5511.50
4CIOUT_UC_FAULT_RESPONSESee FAULT_RESPONSES command
4DReserved
4EReserved
4FOT_FAULT_LIMIT–255.75255.750
50OT_FAULT_RESPONSESee FAULT_RESPONSES command
51OT_WARN_LIMIT–255.75255.750
52UT_WARN_LIMITNot Supported
53UT_FAULT_LIMITNot Supported
54UT_FAULT_RESPONSENot Supported
55VIN_OV_FAULT_LIMITNot Supported
56VIN_OV_FAULT_RESPONSENot Supported
57VIN_OV_WARN_LIMITNot Supported
58VIN_UV_WARN_LIMITNot Supported
59VIN_UV_FAULT_LIMITNot Supported
5AVIN_UV_FAULT_RESPONSENot Supported
5BIIN_OC_FAULT_LIMITNot Supported
5CIIN_OC_FAULT_RESPONSENot Supported
5DIIN_OC_WARN_LIMITNot Supported
5EPOWER_GOOD_ON0See comment0Depends on VOUT_MODE
5FPOWER_GOOD_OFF0See comment0Depends on VOUT_MODE
60TON_DELAY032760
61TON_RISENot Supported
62TON_MAX_FAULT_LIMIT032760
63TON_MAX_FAULT_RESPONSESee FAULT_RESPONSES command
64TOFF_DELAY032760
65TOFF_FALLNot Supported
66TOFF_MAX_WARN_LIMIT03276 or 0x7FFF00x7FFF is a special value meaning there is no limit. See section 16.7 of the PMBus Specification.
67Reserved
68POUT_OP_FAULT_LIMITNot Supported
69POUT_OP_FAULT_RESPONSENot Supported
6APOUT_OP_WARN_LIMITNot Supported
6BPIN_OP_WARN_LIMITNot Supported
6C-77Reserved
78STATUS_BYTERead Only
79STATUS_WORDRead Only
7ASTATUS_VOUTRead Only
7BSTATUS_IOUTRead Only
7CSTATUS_INPUTNot Supported
7DSTATUS_TEMPERATURERead Only
7ESTATUS_CMLRead Only
7FSTATUS_OTHERNot Supported
80STATUS_MFR_SPECIFICNot Supported
81STATUS_FANS_1_2Not Supported
82STATUS_FANS_3_4Not Supported
83-87Reserved
88READ_VINNot Supported
89READ_IINNot Supported
8AREAD_VCAPNot Supported
8BREAD_VOUTRead Only
8CREAD_IOUTRead Only
8DREAD_TEMPERATURE_1Read Only
8EREAD_TEMPERATURE_2Read Only
8FREAD_TEMPERATURE_3Not Supported
90READ_FAN_SPEED_1Not Supported
91READ_FAN_SPEED_2Not Supported
92READ_FAN_SPEED_3Not Supported
93READ_FAN_SPEED_4Not Supported
94READ_DUTY_CYCLENot Supported
95READ_FREQUENCYNot Supported
96READ_POUTNot Supported
97READ_PINNot Supported
98PMBUS_REVISIONRead Only
99MFR_IDn/an/aSee commentThe default is an empty string, all zeros
9AMFR_MODELn/an/aSee commentThe default is an empty string, all zeros
9BMFR_REVISIONn/an/aSee commentThe default is an empty string, all zeros
9CMFR_LOCATIONn/an/aSee commentThe default is an empty string, all zeros
9DMFR_DATEn/an/aSee commentThe default is an empty string, all zeros
9EMFR_SERIALn/an/aSee commentThe default is an empty string, all zeros
9FReserved
A0MFR_VIN_MINNot Supported
A1MFR_VIN_MAXNot Supported
A2MFR_IIN_MAXNot Supported
A3MFR_PIN_MAXNot Supported
A4MFR_VOUT_MINNot Supported
A5MFR_VOUT_MAXNot Supported
A6MFR_IOUT_MAXNot Supported
A7MFR_POUT_MAXNot Supported
A8MFR_TAMBIENT_MAXNot Supported
A9MFR_TAMBIENT_MINNot Supported
AA-AFReserved
B0-BFUSER_DATA_00 -USER_DATA_15Not Supported
C0-CFReserved
D0SEQ_TIMEOUT(MFR_SPECIFIC_00)032760
D1VOUT_CAL_MONITOR (MFR_SPECIFIC_01)See commentSee comment0Depends on VOUT_MODE
(Note this parameter is treated as a SIGNED variable)
D2SYSTEM_RESET_CONFIG (MFR_SPECIFIC_02)n/an/a0
D3SYSTEM_WATCHDOG_CONFIG (MFR_SPECIFIC_03)n/an/a0
D4SYSTEM_WATCHDOG_RESET (MFR_SPECIFIC_04)n/an/a0
D5MONITOR_CONFIG (MFR_SPECIFIC_05)n/an/a0
D6NUM_PAGES (MFR_SPECIFIC_06)0Device dependent0Read Only
D7RUN_TIME_CLOCK (MFR_SPECIFIC_07)n/an/a0
D8RUN_TIME_CLOCK_TRIM (MFR_SPECIFIC_08)n/an/a0
D9ROM_MODE (MFR_SPECIFIC_09)n/an/an/aWrite Only
DAUSER_RAM_00 (MFR_SPECIFIC_10)02550
DBSOFT_RESET (MFR_SPECIFIC_11)n/an/an/aWrite Only
DCRESET_COUNT (MFR_SPECIFIC_12)0655350
DDPIN_SELECTED_RAIL_STATES (MFR_SPECIFIC_13)n/an/a0
DERESEQUENCE (MFR_SPECIFIC_14)00xFFFFn/aWrite Only
DFCONSTANTS (MFR_SPECIFIC_15)n/an/an/aRead Only
E0PWM_SELECT (MFR_SPECIFIC_16)0120
E1PWM_CONFIG (MFR_SPECIFIC_17)n/an/a0
E2PARM_INFO (MFR_SPECIFIC_18)n/an/a0Index is checked to verify that it points to a valid base address
E3PARM_VALUE (MFR_SPECIFIC_19)n/an/a0
E4TEMPERATURE_CAL_GAIN (MFR_SPECIFIC_20)–163816380
E5TEMPERATURE_CAL_OFFSET (MFR_SPECIFIC_21)–255.75255.750
E6SET_BREAKPOINTS (MFR_SPECIFIC_22)

n/a

n/a

0

E7DEBUG_CONTINUE (MFR_SPECIFIC_23)

n/a

n/a

0
E8(MFR_SPECIFIC_24)n/an/a0
E9FAULT_RESPONSES (MFR_SPECIFIC_25)n/an/a0
EALOGGED_FAULTS (MFR_SPECIFIC_26)n/an/an/aOnly valid write is all zeroes.
EBLOGGED_FAULT_DETAIL_INDEX
(MFR_SPECIFIC_27)		0Device dependent0
ECLOGGED_FAULT_DETAIL (MFR_SPECIFIC_28)n/an/a0Read Only
EDLOGGED_PAGE_PEAKS (MFR_SPECIFIC_29)n/an/a0Only valid write is all zeroes.
EELOGGED_COMMON_PEAKS (MFR_SPECIFIC_30)n/an/a0Only valid write is all zeroes.
EFLOGGED_FAULT_DETAIL_ENABLES
(MFR_SPECIFIC_31)		n/an/aSee commentAll logging is enabled by default
F0EXECUTE_FLASH (MFR_SPECIFIC_32)n/an/a0Write Only
F3MFR_STATUS (MFR_SPECIFIC_35)n/an/a0
F4GPI_FAULT_RESPONSES (MFR_SPECIFIC_36)n/an/a0
F5MARGIN_CONFIG (MFR_SPECIFIC_37)n/an/a0
F6SEQ_CONFIG (MFR_SPECIFIC_38)n/an/a0
F7GPO_CONFIG_INDEX (MFR_SPECIFIC_39)0120
F8GPO_CONFIG (MFR_SPECIFIC_40)n/an/a0
F9GPI_CONFIG (MFR_SPECIFIC_41)n/an/a0
FAGPIO_SELECT (MFR_SPECIFIC_42)0n/a0
FBGPIO_CONFIG (MFR_SPECIFIC_43)n/an/a0
FCMISC_CONFIG (MFR_SPECIFIC_44)n/an/a0
FDDEVICE_ID (MFR_SPECIFIC_45)n/an/aDevice dependent
FEMfr_Specific_Extended_CommandNot Supported
FFPMBUS_Extended_CommandNot Supported