Hyundai Micro Electronics
GMS81C2020/GMS81C2120
7. PIN DESCRIPTIONS (GMS81C2020)
VDD
: Supply voltage.
: Circuit ground.
I/O port. R3 pins 1 or 0 written to the Port Direction Reg-
ister can be used as outputs or inputs.
VSS
R40~R43
: R4 is an 8-bit CMOS bidirectional I/O port. R4
AVDD
: Supply voltage to the ladder resistor of ADC cir-
pins 1 or 0 written to the Port Direction Register can be
used as outputs or inputs. In addition, R4 serves the func-
tions of the following special features.
cuit. To enhance the resolution of analog to digital convert-
er, use independent power source as well as possible, other
than digital power source.
AVSS
: ADC circuit ground.
Port pin
Alternate function
RESETB
: Reset the MCU.
R40
T0O (Timer/Counter 0 output)
XI
: Input to the inverting oscillator amplifier and input to
R50~R57
: R5 is an 8-bit CMOS bidirectional I/O port. R5
the internal clock operating circuit.
pins 1 or 0 written to the Port Direction Register can be
used as outputs or inputs. In addition, R5 serves the func-
tions of the various following special features.
XO
: Output from the inverting oscillator amplifier.
SXI
: Input to the internal subsystem clock operating cir-
cuit. In addition, SXI serves the R74 pin when selected by
the code option.
Port pin
Alternate function
SCLK (Serial clock)
R53
R54
R55
R56
SXO
: Output from the inverting subsystem oscillator am-
SIN (Serial data input)
plifier. In addition, SXO serves the R75 pin when selected
by the code option.
SOUT (Serial data output)
PWM1O (PWM1 Output)
T1O (Timer/Counter 1 output)
RA(Vdisp
)
: RA is one-bit high-voltage input only port pin.
In addition, RA serves the functions of the Vdisp special
features. Vdisp is used as a high-voltage input power supply
pin when selected by the mask option..
R60~R67
: R6 is an 8-bit CMOS bidirectional I/O port. R6
pins 1 or 0 written to the Port Direction Register can be
used as outputs or inputs. In addition, R6 is shared with the
ADC input.
Port pin
Alternate function
RA
V
disp (High-voltage input power supply)
Port pin
Alternate function
AN0 (Analog Input 0)
R00~R07
R60
R61
R62
R63
R64
R66
R66
R67
: R0 is an 8-bit high-voltage CMOS bidirectional
AN1 (Analog Input 1)
AN2 (Analog Input 2)
AN3 (Analog Input 3)
AN4 (Analog Input 4)
AN5 (Analog Input 5)
AN6 (Analog Input 6)
AN7 (Analog Input 7)
I/O port. R0 pins 1 or 0 written to the Port Direction Reg-
ister can be used as outputs or inputs. In addition, R0
serves the functions of the various following special fea-
tures.
Port pin
Alternate function
R00
R01
R02
R03
INT0 (External interrupt 0)
INT1 (External interrupt 1)
EC0 (Event counter input)
BUZO (Buzzer driver output)
R70~R73
: R7 is an 8-bit CMOS bidirectional I/O port. R6
pins 1 or 0 written to the Port Direction Register can be
used as outputs or inputs. In addition, R7 is shared with the
ADC input.
R10~R17
: R1 is an 8-bit high-voltage CMOS bidirectional
I/O port. R1 pins 1 or 0 written to the Port Direction Reg-
ister can be used as outputs or inputs.
Port pin
Alternate function
AN8 (Analog Input 8)
AN9 (Analog Input 9)
AN10 (Analog Input 10)
AN11 (Analog Input 11)
R20~R27
: R2 is an 8-bit high-voltage CMOS bidirectional
R70
R71
R72
R73
I/O port. R2 pins 1 or 0 written to the Port Direction Reg-
ister can be used as outputs or inputs.
R30~R35
: R3 is an 6-bit high-voltage CMOS bidirectional
Nov. 1999 Ver 0.0
preliminary
11
HYNIX [ HYNIX SEMICONDUCTOR ]
