C8051F040-TB Silicon Laboratories Inc, C8051F040-TB Datasheet - Page 243

• 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

19.3.2. Master Receiver Mode
Serial data is received on SDA while the serial clock is output on SCL. The SMBus0 interface generates a
START followed by the first data byte containing the address of the target slave and the data direction bit.
In this case the data direction bit (R/W) will be logic 1 to indicate a "READ" operation. The SMBus0 inter-
face receives serial data from the slave and generates the clock on SCL. After each byte is received,
SMBus0 generates an ACK or NACK depending on the state of the AA bit in register SMB0CN. SMBus0
generates a STOP condition to indicate the end of the serial transfer.
19.3.3. Slave Transmitter Mode
Serial data is transmitted on SDA while the serial clock is received on SCL. The SMBus0 interface receives
a START followed by data byte containing the slave address and direction bit. If the received slave address
matches the address held in register SMB0ADR, the SMBus0 interface generates an ACK. SMBus0 will
also ACK if the general call address (0x00) is received and the General Call Address Enable bit
(SMB0ADR.0) is set to logic 1. In this case the data direction bit (R/W) will be logic 1 to indicate a "READ"
operation. The SMBus0 interface receives the clock on SCL and transmits one or more bytes of serial
data, waiting for an ACK from the master after each byte. SMBus0 exits slave mode after receiving a
STOP condition from the master.
S
Interrupt
S
Received by SMBus
Interface
Transmitted by
SMBus Interface
Figure 19.6. Typical Slave Transmitter Sequence
Received by SMBus
Interface
Transmitted by
SMBus Interface
Figure 19.5. Typical Master Receiver Sequence
SLA
SLA
Interrupt
R
R
A
Interrupt
A
Data Byte
Data Byte
Rev. 1.5
C8051F040/1/2/3/4/5/6/7
Interrupt
A
Interrupt
A
S = START
P = STOP
N = NACK
W = WRITE
SLA = Slave Address
Data Byte
S = START
P = STOP
A = ACK
N = NACK
R = READ
SLA = Slave Address
Data Byte
Interrupt
N
Interrupt
Interrupt
P
N
P
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