C8051T601-GMR Silicon Laboratories Inc, C8051T601-GMR Datasheet - Page 132

• Manufacturer Part Number: C8051T601-GMR
• Description: MCU 8-Bit C8051T60x 8051 CISC 8KB EPROM 1.8V/3V 14-Pin QFN EP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051T601-GMR

• Package: 14QFN EP
• Device Core: 8051
• Family Name: C8051T60x
• Maximum Speed: 25 MHz
• Ram Size: 256 Byte
• Program Memory Size: 8 KB
• Operating Supply Voltage: 1.8|3 V
• Data Bus Width: 8 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 8
• Interface Type: I2C/SMBus/UART
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

C8051T600/1/2/3/4/5/6
23.5.2. Read Sequence (Master)
During a read sequence, an SMBus master reads data from a slave device. The master in this transfer will
be a transmitter during the address byte, and a receiver during all data bytes. The SMBus interface gener-
ates the START condition and transmits the first 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 (READ). Serial data is then
received from the slave on SDA while the SMBus outputs the serial clock. The slave transmits one or more
bytes of serial data.
The ACKRQ bit is set to 1 and an interrupt is generated after each received byte. Software must write the
ACK bit at that time to ACK or NACK the received byte.
Writing a 1 to the ACK bit generates an ACK; writing a 0 generates a NACK. Software should write a 0 to
the ACK bit for the last data transfer to transmit a NACK. The interface exits Master Receiver Mode after
the STO bit is set and a STOP is generated. The interface will switch to Master Transmitter Mode if
SMB0DAT is written while an active Master Receiver. Figure 23.6 shows a typical master read sequence.
Two received data bytes are shown, though any number of bytes may be received. Notice that the ‘data
byte transferred’ interrupts occur before the ACK.
132
S
Received by SMBus
Interface
Transmitted by
SMBus Interface
SLA
Figure 23.6. Typical Master Read Sequence
R
A
Interrupt Locations
Data Byte
Rev. 1.2
A
S = START
P = STOP
A = ACK
N = NACK
R = READ
SLA = Slave Address
Data Byte
N
P