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Details, datasheet, quote on part number:NT6868
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| Part: | NT6868 |
| Category: | Interface and Interconnect => Keyboard & Mouse Controllers |
| Description: | Keyboard Controller |
| Company: | Novatek Microelectronics Corp. |
| Datasheet: | Download NT6868 datasheet File size : 216 kB |
| Request For quote: | Find where to buy NT6868
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Datasheet text preview:
NT6868C
Keyboard Controller
Features
Built-in 6502 8-bit CPU 2 MHz CPU operation frequency 4K bytes of ROM 128 bytes of SRAM One 8-bit programmable base timer with 1 - 256 µsec interval n 29 programmable bi-directional I/O pins n 3 LED direct sink pins with internal serial resistors n n n n n n Mask optional for built-in RC oscillator with an external resistor or external ceramic resonator applied n Mask optional for DATA/CLK driving capability n Watch-dog timer n Built-in power-on reset n Built-in low voltage reset n CMOS technology for low power consumption n Available in 40 pin DIP package and 40 pad CHIP FORM
General Description
NT6868C is a single chip micro-controller for keyboard applications. It incorporates a 6502 8-bit CPU core, 4K bytes of ROM and 128 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 that only requires an externally applied or a 4MHz ceramic resonator, and a watch-dog timer that has a resistor preventing 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
26
25
24
23
22
21
20
19
18
17
16 15
P05 P04 P03 P02 P01 P00 RESET P34 P33 P32
P20 P21 P22 P23 P24 P25 P26 P27 LED0 LED1
27 28 29 30 31 32 33 34 35 36 37 38 39 40 1 2 3 4 5
14 13 12
NT6868CH
11 10 9 8 7
NT6868C
6
P31
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
V2.0
NT6868C
Block Diagram
CLK TIMING GENERATOR (RC OSC/Ceramic Resonator: 4MHz) 4 K BYTES ROM
DATA
LED0
LED1
6502 CPU
128 BYTES SRAM + STACK
LED2
I/O PORTS
P00 - P07
INT. CONTROLLER
WATCH DOG TIMER
P10 - P17
P20 - P27 RESET VDD GND POWER-ON RESET/ LOW VOLTAGE RESET BASE TIMER P30 - P34
Pin and Pad Descriptions
Pin No. 1 2 3 4 5 - 9, 11 - 34 10 35 - 37 38 39 40 Pad No. 1 2 3 4 5 - 9, 11 - 34 10 35 - 37 38 39 40 Designation GND NC DATA CLK P30 - P34, P00 - P27 RESET LED0 LED2 VDD R/OSCO OSCI I/O P I/O I/O I/O I O P I Ground pin No connection, recommended to connect VDD or floating I/O, 10K pull-up resistor for communication I/O, 10K pull-up resistor for communication Bi-directional I/O pins RESET signal input pin with internal pull-up resistor; Active low LED direct sink pins Power supply 47K resistor connected for RC OSC or 4MHz ceramic resonator connection No connection for RC OSC connection; for 4MHz ceramic resonator Description
* Under the constraint of the maximum frequency variation, (F/F)max, ±1%, code 3, 7 (ceramic resonator option) must be selected while pins 39 and 40 are connected to a ceramic resonator. If (F/F)max, ±10%, code 1, 5 (RC OSC option), then it is recommended to be selected. Also, connect pin 39 a 47K resistor with, ±1% accuracy to VDD while pin 40 is floating.
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NT6868C
Functional Description
6502 CPU 6502 is an 8-bit CPU. Please refer to 6502 data sheet for more details.
7 ACCUMULATOR A 7 INDEX REGISTER X 7 INDEX REGISTER Y 15 PROGRAM COUNTER PC 7 S 7 S V B D I Z
0 0000 0 SRAM 009F UNUSED 00C0 0 00CF SYSTEM REGISTERS STACK PTR
0
UNUSED
0 STACK POINTER SP 0 C STATUS REGISTER P
EC00
USER ROM
FFFA CARRY ZERO INTERRUPT MASK DECIMAL MODE BREAK OVERFOLW SIGN NMI-L FFFB NMI-H FFFC RST-L FFFD FFFE FFFF RST-H IRQ-L IRQ-H IRQ VECTOR NMI VECTOR
Figure 1. 6502 CPU Registers and Status Flags
Figure 2. NT6868C Memory Map
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