NT6881
5. System Reserved Registers
Address Register
Reset
00H
00H
00H
00H
00H
00H
00H
01H
Bit 7
-
Bit 6
-
Bit 5
-
Bit 4
-
Bit 3
KBD
CKBD
EKBD
IN2
Bit 2
INT1
CINT1
EINT1
IN1
Bit 1
INT0
CINT0
EINT0
OT0
Bit 0
TMR
CTMR
ETMR
IN0
R/W
R
$0000
$0001
$0002
$0003
$0004
$0005
$0006
$0007
IRQFUNC
IRQCLRF
IE_FUNC
IRQUSB
IRQCLRU
IE_USB
BT
-
-
-
-
W
-
-
-
-
R/W
R
SUSP
CSUSP
ESUSP
BT7
STUP
CSTUP
ESTUP
BT6
-
-
-
-
CIN2
EIN2
BT3
CIN1
EIN1
BT2
COT0
EOT0
BT1
CIN0
EIN0
BT0
W
-
-
R/W
W
BT5
-
BT4
-
TCON
-
-
-
-
-
W
ENBT
TM0
P00
P10
P20
P30
LED0
1
$0008
$0009
$000A
$000B
$000C
$000D
$000E
$000F
TMOD
PORT0
PORT1
PORT2
PORT3
LED
00H
FFH
FFH
FFH
1FH
07H
00H
02H
-
P07
P17
P27
-
-
P06
P16
P26
-
-
P05
P15
P25
-
-
P04
P14
P24
P34
-
-
P03
P13
P23
P33
-
TM2
P02
P12
P22
P32
LED2
1
TM1
P01
P11
P21
P31
LED1
0
R/W
R/W
R/W
R/W
R/W
W
-
-
-
CLRWDT
MODE_FG
0
1
0
1
0
W
-
-
-
-
-
-
POF
SUSF
R/W
-: no effect
6. Power-on Reset
7. Timing Generator
Built-in power-on reset circuit can generate a minimum of
5ms pulse to reset the entire chip. User also can use an
This block generates the system timing and control
signals supplied to CPU and on-chip peripherals. The
crystal oscillator generates a 6MHz system clock. It only
generates 3MHz clock for CPU.
external RESET pin to reset the entire chip.
8