C8051F311-GMR Silicon Laboratories Inc, C8051F311-GMR Datasheet - Page 150

• Manufacturer Part Number: C8051F311-GMR
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F31xr

Specifications of C8051F311-GMR

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 25
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 17x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Package: 24QFN EP
• Device Core: 8051
• Family Name: C8051F31x
• Maximum Speed: 25 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 25
• Interface Type: I2C/SMBus/SPI/UART
• On-chip Adc: 17-chx10-bit
• Number Of Timers: 4
• For Use With: 336-1446 - ADAPTER PROGRAM TOOLSTICK F311336-1253 - DEV KIT FOR C8051F310/F311
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

C8051F310/1/2/3/4/5/6/7
14.4.1. SMBus Configuration Register
The SMBus Configuration register (SMB0CF) is used to enable the SMBus Master and/or Slave modes,
select the SMBus clock source, and select the SMBus timing and timeout options. When the ENSMB bit is
set, the SMBus is enabled for all master and slave events. Slave events may be disabled by setting the
INH bit. With slave events inhibited, the SMBus interface will still monitor the SCL and SDA pins; however,
the interface will NACK all received addresses and will not generate any slave interrupts. When the INH bit
is set, all slave events will be inhibited following the next START (interrupts will continue for the duration of
the current transfer).
The SMBCS1-0 bits select the SMBus clock source, which is used only when operating as a master or
when the Free Timeout detection is enabled. When operating as a master, overflows from the selected
source determine the absolute minimum SCL low and high times as defined in Equation 14.1. Note that the
selected clock source may be shared by other peripherals so long as the timer is left running at all times.
For example, Timer 1 overflows may generate the SMBus and UART baud rates simultaneously. Timer
configuration is covered in
The selected clock source should be configured to establish the minimum SCL High and Low times as per
Equation 14.1. When the interface is operating as a master (and SCL is not driven or extended by any
other devices on the bus), the typical SMBus bit rate is approximated by Equation 14.2.
150
Equation 14.1. Minimum SCL High and Low Times
SMBCS1
Table 14.1. SMBus Clock Source Selection
Section “17. Timers” on page
T
Equation 14.2. Typical SMBus Bit Rate
HighMin
0
0
1
1
BitRate
=
SMBCS0
T
LowMin
0
1
0
1
=
f
--------------------------------------------- -
ClockSourceOverflow
Rev. 1.7
=
Timer 2 High Byte Overflow
Timer 2 Low Byte Overflow
--------------------------------------------- -
f
ClockSourceOverflow
SMBus Clock Source
3
Timer 0 Overflow
Timer 1 Overflow
187.
1