HT83F10 HOLTEK [Holtek Semiconductor Inc], HT83F10 Datasheet - Page 19

• Manufacturer Part Number: HT83F10
• Description: Flash Type Voice OTP MCU
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

Programming Considerations
Within the user program, one of the first things to con-
sider is port initialization. After a reset, all of the I/O data
and port control registers will be set high. This means
that all I/O pins will default to an input state, the level of
which depends on the other connected circuitry and
whether pull-high options have been selected. If the port
control registers, PAC, PBC etc., are then programmed
to setup some pins as outputs, these output pins will
have an initial high output value unless the associated
port data registers, PA, PB, etc., are first programmed.
Selecting which pins are inputs and which are outputs
can be achieved byte-wide by loading the correct values
into the appropriate port control register or by program-
ming individual bits in the port control register using the
using these bit control instructions, a read-modify-write
Rev. 1.00
SET [m].i and CLR [m].i instructions. Note that when
PA Input/Output Port
PB Input/Output Port
19
operation takes place. The microcontroller must first
read in the data on the entire port, modify it to the re-
quired new bit values and then rewrite this data back to
the output ports.
Port A has the additional capability of providing wake-up
functions. When the device is in the Power Down Mode,
various methods are available to wake the device up.
One of these is a high to low transition of any of the Port
A pins. Single or multiple pins on Port A can be setup to
have this function.
Read/Write Timing
HT83FXX
May 12, 2009