C8051F131R Silicon Labs, C8051F131R Datasheet - Page 91

• 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

7.
The C8051F12x devices include a second ADC peripheral (ADC2), which consists of an 8-channel, config-
urable analog multiplexer, a programmable gain amplifier, and a 500 ksps, 8-bit successive-approximation-
register ADC with integrated track-and-hold (see block diagram in Figure 7.1). ADC2 is fully configurable
under software control via the Special Function Registers shown in Figure 7.1. The ADC2 subsystem (8-bit
ADC, track-and-hold and PGA) is enabled only when the AD2EN bit in the ADC2 Control register
(ADC2CN) is set to logic 1. The ADC2 subsystem is in low power shutdown when this bit is logic 0. The
voltage reference used by ADC2 is selected as described in
page 113
7.1.
Eight ADC2 channels are available for measurement, as selected by the AMX2SL register (see SFR Defi-
nition 7.2). The PGA amplifies the ADC2 output signal by an amount determined by the states of the
AMP2GN2-0 bits in the ADC2 Configuration register, ADC2CF (SFR Definition 7.3). The PGA can be soft-
ware-programmed for gains of 0.5, 1, 2, or 4. Gain defaults to 0.5 on reset.
Important Note : AIN2 pins also function as Port 1 I/O pins, and must be configured as analog inputs when
used as ADC2 inputs. To configure an AIN2 pin for analog input, set to ‘0’ the corresponding bit in register
P1MDIN. Port 1 pins selected as analog inputs are skipped by the Digital I/O Crossbar. See
“18.1.5. Configuring Port 1 Pins as Analog Inputs” on page 240
the AIN2 pins.
AIN2.0 (P1.0)
AIN2.1 (P1.1)
AIN2.2 (P1.2)
AIN2.3 (P1.3)
AIN2.4 (P1.4)
AIN2.5 (P1.5)
AIN2.6 (P1.6)
AIN2.7 (P1.7)
ADC2 (8-Bit ADC, C8051F12x Only)
Analog Multiplexer and PGA
.
AMX2CF
Figure 7.1. ADC2 Functional Block Diagram
+
+
+
+
-
-
-
-
AMUX
8-to-1
AMX2SL
X
+
-
AV+
AD2EN
ADC2GTH
AGND
Rev. 1.4
ADC2CF
C8051F120/1/2/3/4/5/6/7
ADC
8-Bit
SAR
AV+
ADC2CN
ADC2LTH
Section “9. Voltage Reference” on
for more information on configuring
C8051F130/1/2/3
Start Conversion
8
8
000
001
010
011
1xx
8
16
Write to AD2BUSY
Timer 3 Overflow
CNVSTR2
Timer 2 Overflow
Write to AD0BUSY
(synchronized with
ADC0)
Comp
Dig
AD2WINT
Section
91