BCM4414xG0F4440yzz
3. The unsupported PMBus command code
The BCM Controller Implementation vs.
PMBus™ Specification Rev 1.2
response as described in the Fault Management and Reporting:
nꢀnDeviations from the PMBus specification:
a. PMBus section 10.2.5.3, exceptions
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.
• 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
fault condition
Unmet DC parameter Implementation vs SMBus™ spec
• All powertrain responses are pre-set and cannot
be changed.
PMBus
Interface
SMBus
Rev 2.0
Symbol
Parameter
Units
Min Max Min Max
b. PMBus section 10.6, reporting faults and warnings
[a]
to the Host
VIL
Input Low Voltage
Input High Voltage
Input Leakage per Pin
–
0.99
–
–
0.8
V
V
[a]
• 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.
VIH
2.31
10
2.1 VVDD_IN
[b]
ILEAK_PIN
22
–
5
µA
[a]
V
V
= 3.3V
VDD_IN
[b]
= 5V
BUS
c. PMBus section 10.7, clearing a shutdown due to a fault
2.The BCM accepts 38 PMBus command codes.
Implemented commands execute functions as described in the
PMBus specification.
• 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.
ꢀnDeviations from the PMBus specification:
a. Section 15, fault related commands
d. PMBus Section 10.8.1, corrupted data transmission faults:
• Packet error checking is not supported.
• The limits and Warnings unit is implemented as a
percentage (%) a range from decimal (0 – 100) of the
factory set limits.
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 36 of 43
Rev 1.2
01/2018
VICOR [ VICOR CORPORATION ]
