HT48R03 Holtek Semiconductor, HT48R03 Datasheet - Page 18

• Manufacturer Part Number: HT48R03
• Description: (HT48R01 - HT48R03) 10-Pin MSOP I/O Type 8-Bit OTP MCU
• Manufacturer: Holtek Semiconductor

Input/Output Ports
There are 7 bi-directional input/output lines and 1 input
line in the microcontroller, labeled as PA, which are
mapped to the data memory of [12H]. All of the I/O ports
can be used for input or output operations. For input op-
eration, these ports are non-latching, that is, the inputs
must be ready at the T2 rising edge of instruction MOV
A,[m] (m=12H). For output operation, all the data is
latched and remains unchanged until the output latch is
rewritten. Each I/O line has its own control register
(PAC) to control the input/output configuration (PA7 for
input only). With this control register, a CMOS output or
Schmitt trigger input ( with or without pull-high resistor
structures) can be reconfigured dynamically (i.e.
on-the-fly) under software control ( the PA7 only provide
input mode). To function as an input, the corresponding
latch of the control register must write 1 . The input
source also depends on the control register. If the con-
trol register bit is 1 , the input will read the pad state. If
the control register bit is 0 , the contents of the latches
will move to the internal bus. The latter is possible in the
CMOS is the only configuration. These control register
is mapped to locations 13H. After a chip reset, these in-
put/output lines remain at high levels or floating state
(dependent on pull-high options). Each bit of these in-
put/output latches can be set or cleared by SET [m].i
Rev. 1.00
read-modify-write instruction. For output function,
Input/Output Ports (PA0~PA6)
Input/Output Ports (PA7)
18
tions first input data and then follow the output opera-
tions. For example, SET [m].i , CLR [m].i , CPL [m] ,
ecute the defined operations (bit-operation), and then
write the results back to the latches or the accumulator.
CPLA [m] read the entire port states into the CPU, ex-
Bit No.
Bit No.
Wake up and pull-high function
Each line (except PA7) of PA port supports waking-up
MCU and pull-high function which are controlled by
PAWK, PAPU registers respectively. PA7 hasn t
wake-up and pull-high function.
0~6
0~6
7
7
CLR [m].i (m=12H) instructions. Some instruc-
HT48R01/HT48R02/HT48R03
PAWK0~
PAWK6
PAPU0~
PAPU6
Label
Label
PAWK (15H) Register
PAPU (14H) Register
PAWKn= 0, PAn wake-up is dis-
able
PAWKn=1, PAn wake-up is en-
able
Unused bit, read as 0
PAPUn= 0, PAn pull-up is disable
PAPUn=1, PAn pull-up is enable
Unused bit, read as 0
Function
Function
December 20, 2006