SLVSHK9 December 2024 TPS546B26
PRODUCTION DATA
| CMD Address: | 78h |
| Write Transaction: | N/A |
| Read Transaction: | Read Byte |
| Format: | Unsigned Binary (1 byte) |
| NVM Back-up: | No |
| Updates: | On-the-fly |
The STATUS_BYTE command returns one byte of information with a summary of the most critical faults, such as overvoltage, overcurrent, overtemperature, and so forth. The supported STATUS_BYTE message content is described in the following table. The STATUS_BYTE is equal the low byte of STATUS_WORD. The conditions in the STATUS_BYTE are summary information only. They are asserted to inform the host as to which other STATUS registers should be checked in the event of a fault. Setting and clearing of these bits must be done in the individual status registers. For example, clearing VOUT_OVF in STATUS_VOUT also clears VOUT_OVF in STATUS_BYTE.
Attempts to write STATUS_BYTE will be considered invalid/unsupported data and cause the device to respond by flagging the appropriate status bits and notifying the host according to the PMBus 1.3.1 Part II specification section 10.9.3.
Secondary devices will set all bits to 0b.
Return to Supported PMBus Commands.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| R | R | R | R | R | R | R | R |
| 0 | OFF | OVF | OCF | 0 | OTFW | CML | OTH |
| LEGEND: R/W = Read/Write; R = Read only |
Bit | Field | Access | Reset | Description |
|---|---|---|---|---|
| 7 | Not supported | R | 0b | Not supported and always set to 0b. |
| 6 | OFF | R | 1b | LIVE (unlatched) status bit. 0b: The the device is enabled and converting power. 1b: The device is NOT converting power for any reason including simply not being enabled. |
| 5 | OVF | R | 0b | An output overvoltage fault has occurred. This bit directly reflect the state of
(7Ah) STATUS_VOUT[7] – OVF. If the user wants this fault sourced to be masked and
not trigger SMBALERT, they must do it by masking (7Ah) STATUS_VOUT[7]. Note that secondary devices will set bit OVF to 0. 0b: An output overvoltage fault has NOT occurred. 1b: An output overvoltage fault has occurred. |
| 4 | OCF | R | 0b | An output overcurrent fault has occurred. Per the PMBus spec, this bit can be set
by either (7Bh) STATUS_IOUT[7] OCF or (7Bh) STATUS_IOUT[6] OCUV. (7Bh) STATUS_IOUT[6] OCUV is not a source of SMBALERT, so, if the user wants this
fault source to be masked and not trigger SMBALERT, they must do so by masking the
source bit in (7Bh) STATUS_IOUT 0b: An output overcurrent fault has NOT occurred. 1b: An output overcurrent fault has occurred. |
| 3 | Not supported | R | 0b | Not supported and always set to 0b. |
| 2 | OTFW | R | 0b | OTF or OTW input has been asserted by the programmable temperature limit. 0b: A temperature fault or warning has NOT occurred. 1b: A temperature fault or warning has occurred, the host should check (7Dh) STATUS_TEMPERATURE for more information. |
| 1 | CML | R | 0b | Communications, memory or logic fault has occurred in (7Eh) STATUS_CML. 0b: A communication, memory, logic fault has NOT occurred. 1b: A communication, memory, logic fault has occurred, the host should check (7Eh) STATUS_CML for more information. |
| 0 | OTH | R | 0b | This bit is used to flag faults not covered with the other bit faults in
STATUS_BYTE. In this case, VOUT_MAX_MIN_W, OTF_BG , LOW_VIN, UVF, OCW, OVW, UVW,
PVIN_OVF, or FRST_2_ALRT. 0b: A fault other than those listed above has NOT occurred. 1b: A fault other than those listed above has occurred. The host should check (79h) STATUS_WORD for more information. |