GMS81504 Datasheet, PDF (5/54 Pages) List of Unclassifed Manufacturers – CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER

HYUNDAI MicroElectronics
GMS81504
PIN DESCRIPTIONS
VDD: Supply voltage.
VSS: Circuit Ground.
TEST: For test purposes only. Connect it to VDD.
RESET: Reset the MCU.
XIN: Input to the inverting oscillator amplifier and
input to the internal clock operating circuit.
XOUT: Output from the inverting oscillator amplifier.
R00~R07: R0 is an 8-bit, CMOS, bidirectional I/O
port. As an output port each pin can sink several LS
TTL inputs. R0 pins that have 1 or 0 written to their
Port Direction Mode Register, can be used as outputs
or inputs.
R40~R47: R4 is an 8-bit, CMOS, bidirectional I/O
port. As an output port each pin can sink several LS
TTL inputs. R4 pins that have 1 or 0 written to their
Port Direction Mode Register, can be used as outputs
or inputs.
In addition, Port R40, R41, R44, R46 serve the func-
tions of the various following special features.
Port Pin
R40
R41
R44/EC0
R46
Alternate Function
INT0 (External Interrupt 0)
INT1 (External Interrupt 1)
EC0 (External Count Input to
Timer/Counter 0)
T1O (Timer 1 Clock-Out)
R55, R56, R57: R5 is a 3-bit, CMOS, bidirectional I/O
port. As an output port each pin can sink several LS
TTL inputs. R5 pins that have 1 or 0 written to their
Port Direction Mode Register, can be used as outputs
or inputs. R56 and R57 differs in having internal
pull-ups.
Port R55 serves the functions of special features.
Port Pin
R55
Alternate Function
BUZ (Square wave output for Buzzer
driving)
R64~R67: R6 is an 4-bit, CMOS, bidirectional I/O
port. R64~R67 are bidirectional I/O port. As an output
port each pin can sink several LS TTL inputs.
R64~R67 pins that have 1 or 0 written to their Port
Direction Mode Register, can be used as outputs or
inputs.
R6 serves the analog to digital converter functions of
following.
Port Pin
R64
R65
R66
R67
Alternate Function
AN4 (ADC input 4)
AN5 (ADC input 5)
AN6 (ADC input 6)
AN7 (ADC input 7)
AVDD: Supply voltage to the ladder resistor of ADC
circuit. To enhance the resolution of analog to digital
converter, use independent power source as well as
possible, other than digital power source.
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