C8051F120DK Silicon Laboratories Inc, C8051F120DK Datasheet - Page 259

• Manufacturer Part Number: C8051F120DK
• Description: DEVKIT-F120/21/22/23/24/25/26/27
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F120DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F12x and C8051F13x
• Interface Type: USB
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F120
• Silicon Family Name: C8051F12x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F120, 121, 122, 123, 124, 125, 126, 127
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1224

19. System Management Bus / I2C Bus (SMBus0)
The SMBus0 I/O interface is a two-wire, bi-directional serial bus. SMBus0 is compliant with the System
Management Bus Specification, version 1.1, and compatible with the I2C serial bus. Reads and writes to
the interface by the system controller are byte oriented with the SMBus0 interface autonomously control-
ling the serial transfer of the data. A method of extending the clock-low duration is available to accommo-
date 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.
SMBUS
IRQ
S
L
V
6
S
L
V
5
SMB0ADR
S
L
V
4
B
U
S
Y
Interrupt
Request
B
S
L
V
3
E
N
S
M
B
S
V
7
L
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
T
A
7
Figure 19.1. SMBus0 Block Diagram
SFR Bus
S
T
A
6
SMB0STA
S
T
A
5
S
T
A
4
8
S
T
A
3
SMB0DAT
S
A
T
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
Control
2
SMB0CR
C
R
5
Logic
1
SMB0DAT
Rev. 1.4
C
R
4
Write to
0
C
R
3
C
R
2
C
R
1
Control
C8051F120/1/2/3/4/5/6/7
C
R
0
SDA
Control
SCL
1
0
SYSCLK
FILTER
FILTER
C8051F130/1/2/3
N
N
SDA
SCL
C
R
O
S
S
B
A
R
Port I/O
259