C8051F317-GMR Silicon Laboratories Inc, C8051F317-GMR Datasheet - Page 152

• Manufacturer Part Number: C8051F317-GMR
• Description: MCU 8-Bit C8051F31x 8051 CISC 16KB Flash 3.3V 24-Pin QFN EP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051F317-GMR

• Package: 24QFN EP
• Device Core: 8051
• Family Name: C8051F31x
• Maximum Speed: 25 MHz
• Ram Size: 1.25 KB
• Program Memory Size: 16 KB
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 21
• Interface Type: I2C/SMBus/SPI/UART
• On-chip Adc: 17-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4

C8051F310/1/2/3/4/5/6/7
152
Bit7:
Bit6:
Bit5:
Bit4:
Bit3:
Bit2:
Bits1–0: SMBCS1-SMBCS0: SMBus Clock Source Selection.
ENSMB
R/W
Bit7
ENSMB: SMBus Enable.
This bit enables/disables the SMBus interface. When enabled, the interface constantly mon-
itors the SDA and SCL pins.
0: SMBus interface disabled.
1: SMBus interface enabled.
INH: SMBus Slave Inhibit.
When this bit is set to logic 1, the SMBus does not generate an interrupt when slave events
occur. This effectively removes the SMBus slave from the bus. Master Mode interrupts are
not affected.
0: SMBus Slave Mode enabled.
1: SMBus Slave Mode inhibited.
BUSY: SMBus Busy Indicator.
This bit is set to logic 1 by hardware when a transfer is in progress. It is cleared to logic 0
when a STOP or free-timeout is sensed.
EXTHOLD: SMBus Setup and Hold Time Extension Enable.
This bit controls the SDA setup and hold times according to Table 14.2.
0: SDA Extended Setup and Hold Times disabled.
1: SDA Extended Setup and Hold Times enabled.
SMBTOE: SMBus SCL Timeout Detection Enable.
This bit enables SCL low timeout detection. If set to logic 1, the SMBus forces Timer 3 to
reload while SCL is high and allows Timer 3 to count when SCL goes low. If Timer 3 is con-
figured in split mode (T3SPLIT is set), only the high byte of Timer 3 is held in reload while
SCL is high. Timer 3 should be programmed to generate interrupts at 25 ms, and the
Timer 3 interrupt service routine should reset SMBus communication.
SMBFTE: SMBus Free Timeout Detection Enable.
When this bit is set to logic 1, the bus will be considered free if SCL and SDA remain high for
more than 10 SMBus clock source periods.
These two bits select the SMBus clock source, which is used to generate the SMBus bit
rate. The selected device should be configured according to Equation 14.1.
SMBCS1
SFR Definition 14.1. SMB0CF: SMBus Clock/Configuration
INH
R/W
Bit6
0
0
1
1
SMBCS0
BUSY
Bit5
R
0
1
0
1
EXTHOLD SMBTOE SMBFTE SMBCS1
R/W
Bit4
Timer 2 High Byte Overflow
Timer 2 Low Byte Overflow
SMBus Clock Source
Timer 0 Overflow
Timer 1 Overflow
Rev. 1.7
R/W
Bit3
R/W
Bit2
R/W
Bit1
SFR Address:
SMBCS0 00000000
R/W
Bit0
0xC1
Reset Value