ADUC824 Analog Devices, ADUC824 Datasheet - Page 19

• Manufacturer Part Number: ADUC824
• Description: Precision Analog Microcontroller: 1MIPS 8052 MCU + 8kB Flash + 16/24-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC824

• Mcu Core: 8052
• Mcu Speed (mips): 1
• Sram (bytes): 256Bytes
• Gpio Pins: 34
• Adc # Channels: 4

Pin
No.
1
2
3
4
5
6
7
8
9–11
12
13
14
15
16–19
20, 34, 48
21, 35, 47
Mnemonic
P1.0/T2
P1.1/T2EX
P1.2/DAC/IEXC1 I/O
P1.3/AIN5/IEXC2 I
AV
AGND
REFIN(–)
REFIN(+)
P1.4–P1.6
P1.4/AIN1
P1.5/AIN2
P1.6/AIN3
P1.7/AIN4/DAC I/O
SS
MISO
RESET
P3.0–P3.3
P3.0/RXD
P3.1/TXD
P3.2/INT0
P3.3/INT1
DV
DGND
DD
DD
Type
I/O
I/O
S
S
I
I
I
I
I
I
I
I/O
I
I/O
I/O
I/O
I/O
I/O
S
S
Description
Port 1.0 can function as a digital input or digital output and has a pull-up configuration as
described below for Port 3. P1.0 has an increased current drive sink capability of 10 mA and can
also be used to provide a clock input to Timer 2. When Enabled, Counter 2 is incremented in
response to a negative transition on the T2 input pin.
Port 1.1 can function as a digital input or digital output and has a pull-up configuration as
described below for Port 3. P1.1 has an increased current drive sink capability of 10 mA and
can also be used to provide a control input to Timer 2. When Enabled, a negative transition on
the T2EX input pin will cause a Timer 2 capture or reload event.
Port 1.2. This pin has no digital output driver; it can function as a digital input for which ‘0’
must be written to the port bit. As a digital input, P1.2 must be driven high or low externally.
The voltage output from the DAC can also be configured to appear at this pin. If the DAC
output is not being used, one or both of the excitation current sources (200 µA or 2 × 200 µA)
can be programmed to be sourced at this pin.
Port 1.3. This pin has no digital output driver; it can function as a digital input for which ‘0’ must
be written to the port bit. As a digital input, P1.3 must be driven high or low externally. This
pin can provide an analog input (AIN5) to the auxiliary ADC and one or both of the excitation
current sources (200 µA or 2 × 200 µA) can be programmed to be sourced at this pin.
Analog Supply Voltage, 3 V or 5 V
Analog Ground. Ground reference pin for the analog circuitry
Reference Input, Negative Terminal
Reference Input, Positive Terminal
Port 1.4 to P1.6. These pins have no digital output drivers; they can function as digital inputs,
for which ‘0’ must be written to the respective port bit. As a digital input, these pins must be
driven high or low externally. These port pins also have the following analog functionality:
Primary ADC Channel, Positive Analog Input
Primary ADC Channel, Negative Analog Input
Auxiliary ADC Input or muxed Primary ADC Channel, Positive Analog Input
written to the port bit. As a digital input, P1.7 must be driven high or low externally. This pin can
provide an analog input (AIN4) to the auxiliary ADC or muxed Primary ADC Channel, Negative
Analog Input. The voltage output from the DAC can also be configured to appear at this pin.
Slave Select Input for the SPI Interface. A weak pull-up is present on this pin.
Master Input/Slave Output for the SPI Interface. There is a weak pull-up on this input pin.
Reset Input. A high level on this pin for 24 core clock cycles while the oscillator is running resets
the device. There is a weak pull-down and a Schmitt trigger input stage on this pin. External
POR (power-on reset) circuitry must be added to drive the RESET pin as described later in
this data sheet.
P3.0–P3.3 are bidirectional port pins with internal pull-up resistors. Port 3 pins that have 1s written
to them are pulled high by the internal pull-up resistors, and in that state can be used as inputs.
As inputs, Port 3 pins being pulled externally low will source current because of the internal pull-up
resistors. When driving a 0-to-1 output transition, a strong pull-up is active for two core clock
periods of the instruction cycle. Port 3 pins also have various secondary functions described below.
Receiver Data Input (asynchronous) or Data Input/Output (synchronous) of serial (UART) port.
Transmitter Data Output (asynchronous) or Clock Output (synchronous) of serial (UART) port.
Interrupt 0, programmable edge or level triggered Interrupt input, which can be programmed
to one of two priority levels. This pin can also be used as a gate control input to Timer0.
Interrupt 1, programmable edge-or level-triggered Interrupt input, which can be programmed
to one of two priority levels. This pin can also be used as a gate control input to Timer1.
Digital supply, 3 V or 5 V
Digital ground, ground reference point for the digital circuitry
Port 1.7. This pin has no digital output driver; it can function as a digital input for which ‘0’ must be
PIN FUNCTION DESCRIPTIONS
ADuC824