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M451
May. 4, 2018
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Bus Management (SMBus/PMBus Compatiable)
This section is relevant only when Bus Management feature is supported.
Introduction
The Bus Management is an I
2
C interface through which various devices can communicate with
each other and with the rest of the system. It is based on I
2
C principles of operation. The Bus
Management provides a control bus for system and power management related tasks.
This peripheral is compatible with the SMBUS specification rev 2.0 (
) and
PMBUS specification rev 1.2 (http://pmbus.org/).
The System Management Bus Specification refers to three types of devices.
● A slave is a device that receives or responds to a command.
● A master is a device that issues commands, generates the clocks and terminates the transfer.
● A host is a specialized master that provides the main interface to the system’s CPU. A host
must be a master-slave and must support the SMBus host notify protocol. Only one host is
allowed in a system.
This Bus Management peripheral is based on I
2
C specification rev 2.1.
Device Identification
– slave address
Any device that exists on the Bus Management as a slave has a unique address called the Slave
Address. For reference, the following addresses are reserved and must not be used by or assign
to any Bus Management device. (Refer to SMBus specification for detail information)
Slave Address
Bits 7-1
R/W Bit
Bit 0
Comment
0000 000
0
General Call Address
0000 000
1
START byte
0000 001
X
CBUS address
0000 010
X
Address reserved for different bus format
0000 011
X
Reserved for future use
0000 1XX
X
Reserved for future use
0101 000
X
Reserved for ACCESS.bus host
0110 111
X
Reserved for ACCESS.bus default address
1111 0XX
X
10-bit slave addressing
1111 1XX
X
Reserved for future use
0001 000
X
SMBus Host
0001 100
X
SMBus Alert Response Address
1100 001
X
SMBus Device Default Address
Table 6-33 Reserved SMBus Address
Bus protocols
There are eleven possible command protocols for any given device. A device may use any or all
Содержание ARM Cortex NuMicro M451 Series
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Страница 324: ...M451 May 4 2018 Page 324 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL Figure 6 4 18 Checksum Calculation Flow...
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Страница 625: ...M451 May 4 2018 Page 625 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL 00 5 bits 01 6 bits 10 7 bits 11 8 bits...
Страница 721: ...M451 May 4 2018 Page 721 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL the SCL line 1 0 Reserved Reserved...
Страница 1001: ...M451 May 4 2018 Page 1001 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL LQFP 64L 10x10x1 4 mm footprint 2 0 mm 9 2...
Страница 1002: ...M451 May 4 2018 Page 1002 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL LQFP 64L 7x7x1 4 mm footprint 2 0 mm 9 3...
Страница 1003: ...M451 May 4 2018 Page 1003 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL LQFP 48L 7x7x1 4mm footprint 2 0mm 9 4...