NT6880
Keyboard Controller
Features
T
T
T
T
T
T
T
Built-in 6502 8-bit CPU
2 MHz CPU operation frequency
5K bytes of ROM
160 bytes of SRAM
One 8-bit programmable base timer with
1 - 256
碌sec
interval
29 programmable bi-directional I/O pins
3 LED direct sink pins
T
T
T
T
T
T
T
Mask optional for built-in RC oscillator with an
external resistor or external ceramic resonator applied
Mask optional for DATA/CLK driving capability
Watch-dog timer reset
Built-in power-on reset
Built-in low voltage reset
CMOS technology for low power consumption
Available in 40 pin DIP package and 40 pad Chip
Form
General Description
The NT6880 is a single chip micro-controller for
keyboard applications. It incorporates a 6502 8-bit CPU
core, 5K bytes of ROM and 160 bytes of RAM used as
working RAM and stack area. It also includes 29
programmable bi-directional I/O pins and one 8-bit pre-
loadable base timer. Additionally, it includes a built-in
low voltage reset, a 4MHz RC oscillator requiring an
externally applied resistor or a 4MHz ceramic resonator
and a watch-dog timer that prevents system standstill.
Pin Configuration
Pad Configuration
P
1
7
P
1
6
P
1
5
P
1
4
P
1
3
P
1
2
P
1
1
P
1
0
P
0
7
P
0
6
GND
NC
DATA
CLK
P30
P31
P32
P33
P34
RESET
P00
P01
P02
P03
P04
P05
P06
P07
P10
P11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
OSCI
R/OSCO
V
DD
LED2
LED1
LED0
P27
P26
P25
P24
P23
P22
P21
P20
P17
P16
P15
P14
P13
P12
LED1
36
P20
P21
P22
P23
P24
P25
P26
P27
LED0
27
28
29
30
31
32
33
34
35
37
38
39
40
1
2
3
4
5
6
P31
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
P05
P04
P03
P02
P01
P00
RESET
P34
P33
P32
NT6880
NT6880H
L
E
D
2
V
D
D
R
/
O
S
C
O
O
S
C
I
G
N
D
N
C
D
A
T
A
C
L
K
P
3
0
1
V1.0