C8051F236 Silicon Laboratories Inc, C8051F236 Datasheet - Page 50

• Manufacturer Part Number: C8051F236
• Description: IC 8051 MCU 8K FLASH 48TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F2xxr

Specifications of C8051F236

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 32
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 48-TQFP, 48-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

C8051F2xx
7.
The voltage reference circuit selects between an externally connected reference and the power supply
voltage (V
An external reference can be connected to the VREF pin and selected by setting the REF0CN special
function register per Figure 7.1. The external reference supply must be between V
may also be selected using REF0CN per SFR Definition 7.1. The electrical specifications for the Voltage
Reference are given in Table 7.1.
50
Bits7–2: UNUSED. Read = 00000b; Write = don't care
Bit1–0:
R/W
Bit7
Voltage Reference (C8051F206/220/221/226)
-
Vref (external)
DD
REFSL1– REFSL0: Voltage reference selection.
Bits control which reference is selected.
00: External VREF source is selected.
01: Reserved.
10: Reserved.
11: V
). (See Figure 7.1).
Vdd
R/W
Bit6
Figure 7.1. Voltage Reference Functional Block Diagram
DD
-
selected as VREF source.
SFR Definition 7.1. REF0CN: Reference Control
R/W
Bit5
-
R/W
Bit4
-
Rev. 1.6
R/W
Bit3
-
2
R/W
Bit2
-
REFSL1
Set REF0CN to:
00: Use external Vref
11: Use Vdd
REF0CN[1:0]
R/W
Bit1
DD
REFSL0
R/W
Bit0
– 0.3 V and 1 V. V
To ADC Ref
SFR Address:
Reset Value
00000000
0xD1
DD