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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
On-Chip Debug Support – OCDS
There is an EV chip named HT66VM5440 which is used to emulate the HT66FM5440 device. The
EV chip device also provides an "On-Chip Debug" function to debug the real MCU device during
the development process. The EV chip and the real MCU device are almost functionally compatible
except for "On-Chip Debug" function. Users can use the EV chip device to emulate the real chip
device behavior by connecting the OCDSDA and OCDSCK pins to the Holtek HT-IDE development
tools. The OCDSDA pin is the OCDS Data/Address input/output pin while the OCDSCK pin is
the OCDS clock input pin. When users use the EV chip for debugging, other functions which are
shared with the OCDSDA and OCDSCK pins in the device will have no effect in the EV chip.
However, the two OCDS pins which are pin-shared with the ICP programming pins are still used
as the Flash Memory programming pins for ICP. For more detailed OCDS information, refer to the
corresponding document named "Holtek e-Link for 8-bit MCU OCDS User’s Guide".
Holtek e-Link Pins
EV Chip Pins
Pin Description
OCDSDA
OCDSDA
On-Chip Deb�g S�pport Data/Address inp�t/o�tp�t
OCDSCK
OCDSCK
On-Chip Deb�g S�pport Clock inp�t
VDD
VDD
Power S�pply
VSS
VSS
Gro�nd
Data Memory
The Data Memory is a volatile area of 8-bit wide RAM internal memory and is the location where
temporary information is stored.
Categorized into two types, the first of these is an area of RAM, known as the Special Function Data
Memory. These registers have fixed locations and are necessary for correct operation of the device.
Many of these registers can be read from and written to directly under program control, however,
some remain protected from user manipulation. The second area of Data Memory is known as the
General Purpose Data Memory, which is reserved for general purpose use. All locations within this
area are read and write accessible under program control.
S
witching between the different Data Memory sectors is achieved by properly setting the Memory
Pointers to correct value if using indirect addressing method.
Structure
The Data Memory is subdivided into several sectors, all of which are implemented in 8-bit wide
RAM. The Special Purpose Data Memory registers are accessible in all sectors, with the exception
of several registers which are only accessible in Sector 1.
T
he address range of the Special Purpose
Data Memory for the device is from 00H to 7FH while the General Purpose Data Memory address
range is from 80H to FFH.
Special Purpose
Data Memory
General Purpose
Data Memory
Located Sectors
Capacity
Sector: Address
0� 1� �
3�4�
0: �0H~FFH
1: �0H~FFH
�: �0H~FFH
Data Memory Summary