Datasheet

ADuC832 Data Sheet
Rev. B | Page 24 of 92
Pin No.
Mnemonic MQFP LFCSP Type Description
XTAL2 33 35 O Output of the Inverting Oscillator Amplifier.
P2.4/A12/A20 36 39 I/O Input/Output Port 2 (P2.4). Port 2 is a bidirectional port with internal pull-up resistors.
Port 2 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 2 pins being pulled
externally low sources current because of the internal pull-up resistors.
I/O External Memory Addresses (A12/A20). Port 2 emits the high order address bytes
during fetches from external program memory and middle and high order address
bytes during accesses to the external 24-bit external data memory space.
P2.5/A13/A21 37 40 I/O Input/Output Port 2 (P2.5). Port 2 is a bidirectional port with internal pull-up resistors.
Port 2 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 2 pins being pulled
externally low sources current because of the internal pull-up resistors.
I/O External Memory Addresses (A13/A21). Port 2 emits the high order address bytes
during fetches from external program memory and middle and high order address
bytes during accesses to the external 24-bit external data memory space.
P2.6/PWM0/A14/A22 38 41 I/O Input/Output Port 2 (P2.6). Port 2 is a bidirectional port with internal pull-up resistors.
Port 2 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 2 pins being pulled
externally low sources current because of the internal pull-up resistors.
O PWM0 Voltage Output (PWM0). PWM outputs can be configured to use Port 2.6 and
Port 2.7 or Port 3.4 and Port 3.3
I/O External Memory Addresses (A14/A22). Port 2 emits the high order address bytes
during fetches from external program memory and middle and high order address
bytes during accesses to the external 24-bit external data memory space.
P2.7/PWM1/A15/A23 39 42 I/O Input/Output Port 2 (P2.7). Port 2 is a bidirectional port with internal pull-up resistors.
Port 2 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 2 pins being pulled
externally low sources current because of the internal pull-up resistors.
O PWM1 Voltage Output (PWM1). See the ADuC832 Configuration SFR (CFG832) section
for further information.
I/O External Memory Addresses (A15/A23). Port 2 emits the high order address bytes
during fetches from external program memory and middle and high order address
bytes during accesses to the external 24-bit external data memory space.
EA
40 43 I External Access Enable, Logic Input. When held high, this input enables the device to
fetch code from internal program memory locations 0000H to 1FFFH. When held low,
this input enables the device to fetch all instructions from external program memory.
This pin should not be left floating.
PSEN
41 44 O Program Store Enable, Logic Output. This output is a control signal that enables the
external program memory to the bus during external fetch operations. It is active
every six oscillator periods except during external data memory accesses. This pin
remains high during internal program execution.
PSEN
can also be used to enable
serial download mode when pulled low through a resistor on power-up or reset.
ALE 42 45 O Address Latch Enable, Logic Output. This output is used to latch the low byte (and
page byte for 24-bit address space accesses) of the address into external memory
during normal operation. It is activated every six oscillator periods except during an
external data memory access.
P0.0/AD0 43 46 I/O Input/Output Port 0 (P0.0). Port 0 is an 8-Bit Open-Drain Bidirectional I/O Port. Port 0
pins that have 1s written to them float and in that state can be used as high
impedance inputs.
I/O External Memory Address and Data (AD0). Port 0 is also the multiplexed low order
address and data bus during accesses to external program or data memory. In this
application, it uses strong internal pull-ups when emitting 1s.
P0.1/AD1 44 47 I/O Input/Output Port 0 (P0.1). Port 0 is an 8-Bit Open-Drain Bidirectional I/O Port. Port 0
pins that have 1s written to them float and in that state can be used as high
impedance inputs.
I/O External Memory Address and Data (AD1). Port 0 is also the multiplexed low order
address and data bus during accesses to external program or data memory. In this
application, it uses strong internal pull-ups when emitting 1s.