C8051F321 Silicon Laboratories Inc, C8051F321 Datasheet - Page 43

• Manufacturer Part Number: C8051F321
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F321

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

5.3.2. Tracking Modes
The AD0TM bit in register ADC0CN controls the ADC0 track-and-hold mode. In its default state, the ADC0 input is
continuously tracked, except when a conversion is in progress. When the AD0TM bit is logic 1, ADC0 operates in
low-power track-and-hold mode. In this mode, each conversion is preceded by a tracking period of 3 SAR clocks
(after the start-of-conversion signal). When the CNVSTR signal is used to initiate conversions in low-power tracking
mode, ADC0 tracks only when CNVSTR is low; conversion begins on the rising edge of CNVSTR (see Figure 5.3).
Tracking can also be disabled (shutdown) when the device is in low power standby or sleep modes. Low-power track-
and-hold mode is also useful when AMUX settings are frequently changed, due to the settling time requirements
described in
(AD0CM[2:0]=000, 001,010
Timer 1, Timer 3 Overflow
Write '1' to AD0BUSY,
Section “5.3.3. Settling Time Requirements” on page
(AD0CM[2:0]=100)
Timer 0, Timer 2,
Figure 5.3. 10-Bit ADC Track and Conversion Example Timing
SAR Clocks
SAR Clocks
SAR Clocks
AD0TM=1
AD0TM=0
011, 101)
AD0TM=1
AD0TM=0
CNVSTR
Low Power
or Convert
Low Power
or Convert
Track or
Convert
A. ADC0 Timing for External Trigger Source
Track or Convert
B. ADC0 Timing for Internal Trigger Source
1
1
Track
2
2
Track
3
3
4
4
Rev. 1.1
1
Convert
5
5
2
6
6
3
7
7
44.
4
8
Convert
8
Convert
Convert
5
9
9
6
10 11 12
10 11
7
8
C8051F320/1
9
13 14
10 11
Low Power Mode
Track
Low Power
Mode
Track
43