C8051F131R Silicon Labs, C8051F131R Datasheet - Page 117

• Manufacturer Part Number: C8051F131R
• Description: 8-bit Microcontrollers - MCU 128kB 100MIPS 8448B RAM
• Manufacturer: Silicon Labs

Specifications of C8051F131R

• Product Category: 8-bit Microcontrollers - MCU
• Core: 8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 100 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8.25 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 2.7 V to 3.6 V
• Package / Case: TQFP-64
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 9
• Data Rom Size: 64 KB
• Interface Type: I2C, SMBus, SPI, UART
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 32
• Number Of Timers: 16 bit
• Processor Series: C8051
• Program Memory Type: Flash
• Factory Pack Quantity: 500
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 3 V

9.3.
On the C8051F130/1/2/3 devices, the VREF0 pin provides a voltage reference input for ADC0, which can
be connected to an external precision reference or the internal voltage reference, as shown in Figure 9.3.
The REF0CN register for the C8051F130/1/2/3 is described in SFR Definition 9.3.
Bits7–5: UNUSED. Read = 000b; Write = don’t care.
Bits4–3: Reserved: Must be written to 0.
Bit2:
Bit1:
Bit0:
SFR Page:
SFR Address:
Figure 9.3. Voltage Reference Functional Block Diagram (C8051F130/1/2/3)
R/W
Bit7
-
Reference Configuration on the C8051F130/1/2/3
SFR Definition 9.3. REF0CN: Reference Control (C8051F130/1/2/3)
TEMPE: Temperature Sensor Enable Bit.
0: Internal Temperature Sensor Off.
1: Internal Temperature Sensor On.
BIASE: ADC/DAC Bias Generator Enable Bit. (Must be ‘1’ if using ADC or VREF).
0: Internal Bias Generator Off.
1: Internal Bias Generator On.
REFBE: Internal Reference Buffer Enable Bit.
0: Internal Reference Buffer Off.
1: Internal Reference Buffer On. Internal voltage reference is driven on the VREF pin.
0
0xD1
R/W
Bit6
Reference
-
External
Voltage
Circuit
DGND
VDD
Recommended Bypass
4.7F
R/W
Bit5
R1
-
Capacitors
+
Reserved Reserved
0.1F
R/W
Bit4
VREF0
VREF
Rev. 1.4
R/W
Bit3
C8051F120/1/2/3/4/5/6/7
REF0CN
x2
Ref
ADC0
TEMPE
R/W
Bit2
Band-Gap
C8051F130/1/2/3
Bias to ADC
1.2V
EN
BIASE
R/W
Bit1
REFBE
R/W
Bit0
00000000
Reset Value
117