C8051T631-GM Silicon Laboratories Inc, C8051T631-GM Datasheet - Page 34
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C8051T631-GM
Manufacturer Part Number
C8051T631-GM
Description
IC MCU 8KB 20PIN QFN
Manufacturer
Silicon Laboratories Inc
Series
C8051T63xr
Specifications of C8051T631-GM
Core Processor
8051
Core Size
8-Bit
Speed
25MHz
Connectivity
SMBus (2-Wire/I²C), SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
17
Program Memory Size
8KB (8K x 8)
Program Memory Type
OTP
Ram Size
768 x 8
Voltage - Supply (vcc/vdd)
1.8 V ~ 3.6 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
20-QFN
Processor Series
C8051T6x
Core
8051
Data Bus Width
8 bit
Data Ram Size
768 B
Interface Type
UART, SPI, SMBus
Maximum Clock Frequency
25 MHz
Number Of Programmable I/os
17
Number Of Timers
4 x 16-bit
Operating Supply Voltage
1.8 V to 3.6 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
PK51, CA51, A51, ULINK2
Development Tools By Supplier
C8051T630DK
Minimum Operating Temperature
- 40 C
For Use With
336-1464 - KIT DEV FOR C8051T630 FAMILY
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Details
Other names
336-1459-5
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
C8051T631-GM
Manufacturer:
Silicon
Quantity:
91
C8051T630/1/2/3/4/5
6.1. Output Code Formatting
The ADC measures the input voltage with reference to GND. The registers ADC0H and ADC0L contain the
high and low bytes of the output conversion code from the ADC at the completion of each conversion. Data
can be right-justified or left-justified, depending on the setting of the AD0LJST bit. Conversion codes are
represented as 10-bit unsigned integers. Inputs are measured from 0 to VREF x 1023/1024. Example
codes are shown below for both right-justified and left-justified data. Unused bits in the ADC0H and ADC0L
registers are set to 0.
6.2. 8-Bit Mode
Setting the ADC08BE bit in register ADC0CF to 1 will put the ADC in 8-bit mode. In 8-bit mode, only the 8
MSBs of data are converted, and the ADC0H register holds the results. The AD0LJST bit is ignored for 8-
bit mode. 8-bit conversions take two fewer SAR clock cycles than 10-bit conversions, so the conversion is
completed faster, and a 500 ksps sampling rate can be achieved with a slower SAR clock.
6.3. Modes of Operation
ADC0 has a maximum conversion speed of 500 ksps. The ADC0 conversion clock is a divided version of
the system clock, determined by the AD0SC bits in the ADC0CF register.
6.3.1. Starting a Conversion
A conversion can be initiated in one of six ways, depending on the programmed states of the ADC0 Start of
Conversion Mode bits (AD0CM2–0) in register ADC0CN. Conversions may be initiated by one of the fol-
lowing:
1. Writing a 1 to the AD0BUSY bit of register ADC0CN
2. A Timer 0 overflow (i.e., timed continuous conversions)
3. A Timer 2 overflow
4. A Timer 1 overflow
5. A rising edge on the CNVSTR input signal
6. A Timer 3 overflow
Writing a 1 to AD0BUSY provides software control of ADC0 whereby conversions are performed "on-
demand". During conversion, the AD0BUSY bit is set to logic 1 and reset to logic 0 when the conversion is
complete. The falling edge of AD0BUSY triggers an interrupt (when enabled) and sets the ADC0 interrupt
flag (AD0INT). Note: When polling for ADC conversion completions, the ADC0 interrupt flag (AD0INT)
should be used. Converted data is available in the ADC0 data registers, ADC0H:ADC0L, when bit AD0INT
is logic 1. Note that when Timer 2 or Timer 3 overflows are used as the conversion source, Low Byte over-
flows are used if Timer 2/3 is in 8-bit mode; High byte overflows are used if Timer 2/3 is in 16-bit mode.
See Section “24. Timers” on page 169 for timer configuration.
Important Note About Using CNVSTR: The CNVSTR input pin also functions as a Port I/O pin. When the
CNVSTR input is used as the ADC0 conversion source, the associated pin should be skipped by the Digi-
tal Crossbar. See Section “20. Port Input/Output” on page 109 for details on Port I/O configuration.
34
Input Voltage
VREF x 1023/1024
VREF x 512/1024
VREF x 256/1024
0
(AD0LJST = 0)
0x03FF
0x0000
Right-Justified ADC0H:ADC0L
0x0200
0x0100
Rev. 1.0
Left-Justified ADC0H:ADC0L
(AD0LJST = 1)
0xFFC0
0x8000
0x4000
0x0000