C8051F040-TB Silicon Laboratories Inc, C8051F040-TB Datasheet - Page 239

• Manufacturer Part Number: C8051F040-TB
• Description: BOARD PROTOTYPING W/C8051F040
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F040-TB

• Contents: Board
• Processor To Be Evaluated: C8051F04x
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F040
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

19. System Management BUS/I
The SMBus0 I/O interface is a two-wire, bi-directional serial bus. SMBus0 is compliant with the System
Management Bus Specification, version 2, and compatible with the I
interface by the system controller are byte oriented with the SMBus0 interface autonomously controlling
the serial transfer of the data. A method of extending the clock-low duration is available to accommodate
devices with different speed capabilities on the same bus.
SMBus0 may operate as a master and/or slave, and may function on a bus with multiple masters. SMBus0
provides control of SDA (serial data), SCL (serial clock) generation and synchronization, arbitration logic,
and START/STOP control and generation. SMBus0 is controlled by SFRs as described in
page
SMBUS
IRQ
245.
S
L
V
6
S
L
V
5
SMB0ADR
S
L
V
4
B
U
S
Y
Interrupt
Request
B
S
L
V
3
M
E
N
S
B
7
S
L
V
2
SMB0CN
S
T
A
A
S
L
V
1
O
S
T
S
L
V
0
S
I
G
C
A
A
F
T
E
B
O
T
E
SFR Bus
0000000b
SMBUS CONTROL LOGIC
Arbitration
SCL Synchronization
Status Generation
SCL Generation (Master Mode)
IRQ Generation
A
7 MSBs
S
A
T
7
Figure 19.1. SMBus0 Block Diagram
S
A
SFR Bus
T
6
SMB0STA
S
T
A
5
S
T
A
4
8
S
T
A
3
SMB0DAT
S
T
A
2
Read
S
T
A
1
7
S
T
A
0
6
8
SMB0DAT
5
4
C
R
7
3
C
R
6
Clock Divide
Data Path
8
2
Control
2
SMB0CR
C
R
5
C BUS (SMBUS0)
Logic
1
SMB0DAT
Rev. 1.5
C
R
4
Write to
0
C
R
3
C
R
2
C
R
1
Control
C8051F040/1/2/3/4/5/6/7
C
R
0
SDA
Control
SCL
1
0
SYSCLK
FILTER
FILTER
2
C serial bus. Reads and writes to the
N
N
SDA
SCL
C
R
O
R
S
S
B
A
Section 19.4 on
Port I/O
239