
TE
CH
tm
T81L0003B
8.2. External Register Table ( for LVR, High/ Normal Driving) 
Register Address 
A15…A5-A0 
Hex 
100… 0010 1011 
802bH
PWMC2 
100… 0011 0000
8030H 
Port3 HDS Port3 I/O high driving set** 
100… 0011 0010
8032H 
Port1 HDS Port1 I/O high driving set**
Note :  
* 
LVR (Low Voltage Reset) address : 802bH, read/write 
MSB                                                                 LSB 
Bit 7
Bit 6
Bit5
Bit 4
LVR[7] 
LVR[6] 
    LVR[7] : if LVR[7] write ‘1’, low voltage reset function enable. 
            default is ‘0’, low voltage reset function disable. 
    LVR[6] : if LVR[6] write ‘1’= 2.1V reset. if LVR[6] write ‘0’= 2.8V reset. 
            default is ‘0’= 2.8V reset. 
** Port I/O high driving set 
   if write ‘0’ = set I/O to high driving current mode. 
   if write ‘1’ = set I/O to normal driving current mode. 
   default is set ‘1’. 
Port 3 high driving address : 8030H 
MSB                                                                 LSB 
Bit 7
Bit 6
Bit5
Bit 4
Port 1 high driving address : 8032H 
MSB                                                                 LSB 
Bit 7
Bit 6
Bit5
Bit 4
Port1.7
Port1.6
Port1.5
Port1.4
8.3. I/O Ports 
Port1 
Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. Port 1 output buffers can sink/source four external TTL 
device inputs. When port 1 pins are written as 1’s, these pins are pulled high by the internal pull-ups and can be used as 
inputs. As inputs, Port 1 pins that are externally being pulled low will source current because of the internal pull-ups. 
Port 3 
Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. Port 3 output buffers can sink/source four external TTL 
device inputs. When port 3 pins are written as 1’s, these pins are pulled high by the internal pull-ups and can be used as 
inputs. As inputs, Port 3 pins that are externally being pulled low will source current because of the internal pull-ups. 
Port 3 also serves the functions of various special features, as listed below: 
P3.0 RXD (serial input port) 
P3.1 TXD (serial output port) 
P3.2 INT0 (external interrupt 0) 
P3.3 INT1 (external interrupt 1) 
P3.4 T0 (timer 0 external input) 
TM Technology Inc. reserves the right 
P. 9              
Publication Date: NOV. 2005 
to change products or specifications without notice.                                  Revision:A
Name 
Comments 
LVR (Low Voltage Reset)* 
Bit 3
Bit 2
Bit1
Bit 0 
Reserved 
Bit 3
Port3.3
Bit 2
Port3.2
Bit1
Port3.1
Bit 0 
Port3.0 
Port3.4
Bit 3
Port1.3
Bit 2
Port1.2
Bit1
Port1.1
Bit 0 
Port1.0