GMS77C1001 Datasheet, PDF (9/44 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS77C1000/GMS77C1001
5. PIN FUNCTION
V_DD: Supply voltage.
V_SS: Circuit ground.
RESET: Reset the MCU.
X_IN: Input to the inverting oscillator amplifier and input to
the internal main clock operating circuit.
X_OUT: Output from the inverting oscillator amplifier.
RA0~RA3: RA is an 4-bit, CMOS, bidirectional I/O port.
RA pins can be used as outputs or inputs according to “0”
or “1” written the their Port Direction Register(TRISA).
RB0~RB7: RB is a 8-bit, CMOS, bidirectional I/O port.
RB pins can be used as outputs or inputs according to “0”
or “1” written the their Port Direction Register(TRISB).
EC0: EC0 is an external clock input to Timer0. It should
be tied to V_SS or V_DD, if not in use, to reduce current con-
sumption.
PIN NAME
DIP, SOP
Pin No.
V_DD
14
V_SS
5
RESET
4
X_IN
16
X_OUT
15
RA0
17
RA1
18
RA2
1
RA3
2
RB0
6
RB1
7
RB2
8
RB3
9
RB4
10
RB5
11
RB6
12
RB7
13
EC0
3
SSOP
Pin No.
15,16
5,6
4
18
17
19
20
1
2
7
8
9
10
11
12
13
14
3
In/Out
Input
Levels
Function
P
-
Supply voltage
P
-
Circuit ground
Reset signal input/programming voltage input. This pin is an active low
I
ST reset to the device. Voltage on the RESET pin must not exceed V_DD to
avoid unintended entering of programming mode.
I
ST Oscillator crystal input/external clock source input
Oscillator crystal output. Connects to crystal or resonator in crystal oscilla-
O
-
tor mode. In RC mode, X_OUT pin outputs CLKOUT which has 1/4 the fre-
quency of X_IN, and denotes the instruction cycle rate.
I/O
TTL
I/O
TTL
4-bit bi-directional I/O ports
I/O
TTL
I/O
TTL
I/O
TTL
I/O
TTL
I/O
TTL
I/O
TTL
8-bit bi-directional I/O ports
I/O
TTL
I/O
TTL
I/O
TTL
I/O
TTL
I
ST
Clock input to Timer0. Must be tied to V_DD or V_SS, if not in use, to reduce
current consumption.
TABLE 5-1 PINOUT DESCRIPTION
Legend : I =input, O = output, I/O = input/output, P = power, - = Not used, TTL = TTL input, ST = Schmitt Trigger input
6
July. 2001 Ver. 1.1