BCM3814x60E15A3yzz
3. The unsupported PMBus command code response as
The BCM Controller Implementation vs.
PMBus™ Specification Rev 1.2
The BCM controller is an I2C™ compliant, SMBus™ compatible
device and PMBus command compliant device. This section denotes
some deviation, perceived as differences from the PMBus Part I and
Part II specification Rev 1.2.
described in the Fault Management and Reporting:
nꢀnDeviations from the PMBus specification:
a. PMBus section 10.2.5.3, exceptions
• The busy bit of the STATUS_BYTE as implemented can
be cleared (80h). In order to maintain compatibility with
the specification, (40h) can also be used.
1. The PMBus interface meets all Part I and II PMBus specification
requirements with the following differences to the
transport requirement.
ꢀnManufacturer Implementation of the PMBus Spec
a. PMBus section 10.5, setting the response to a detected
Unmet DC parameter Implementation vs SMBus™ spec
fault condition
PMBus
Interface
SMBus
Rev 2.0
• All powertrain responses are pre-set and cannot be
changed.
Symbol
Parameter
Units
Min Max Min Max
b. PMBus section 10.6, reporting faults and warnings
[a]
VIL
Input Low Voltage
Input High Voltage
Input Leakage per Pin
-
0.99
-
-
0.8
V
V
to the Host.
[a]
VIH
2.31
10
2.1 VVDD_IN
• SMBALERT# signal and Direct PMBus Device to Host
Communication are not supported. However, the
PMBus™ interface will set the corresponding fault status
bits and will wait for the host to poll.
[b]
ILEAK_PIN
22
-
5
µA
[a]
V
V
= 3.3V
= 5V
VDD_IN
[b]
BUS
c. PMBus section 10.7, clearing a shutdown due to a fault
2.The BCM accepts 38 PMBus command codes.
• There is no RESET pin or EN pin in the BCM.
Cycling power to the BCM will not clear a BCM
Shutdown. The BCM will clear itself once the fault
condition is removed.
Implemented commands execute functions as described in the
PMBus specification.
ꢀnDeviations from the PMBus specification:
a. Section 15, fault related commands
d. PMBus Section 10.8.1, corrupted data transmission faults:
• The Limits and Warnings unit is implemented as a
percentage (%) range from decimal (0 – 100) of the
factory set limits.
• Packet error checking is not supported.
Data Transmission Faults Implementation
This section describes data transmission faults as implemented in the BCM controller.
Response to Host
STATUS_BYTE
STATUS_CML
Section
Description
Notes
Unsupported
NAK
FFh
CML
Other Fault
Data
10.8.1
10.8.2
10.8.3
Corrupted data
No response; PEC not supported
Sending too few bits
Reading too few bits
X
X
X
X
Host sends or reads too
few bytes
10.8.4
X
X
Host sends too many
bytes
10.8.5
10.8.6
X
X
X
X
X
Reading too many bytes
X
X
X
Device will ACK own address
BUSY bit in STATUS_BYTE even if
STATUS_WORD is set
10.8.7
Device busy
BCM® in a VIA Package
Page 35 of 41
Rev 2.0
02/2018
VICOR [ VICOR CORPORATION ]
