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Rev. 1.40
26
March 29, 2019
Rev. 1.40
27
March 29, 2019
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
Structure
Divided into two sections, the first of these is an area of RAM where special function registers are
located. These registers have fixed locations and are necessary for correct operation of the devices.
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 reserved for
general purpose use. All locations within this area are read and write accessible under program
control.
The overall Data Memory is subdivided into two banks. The Special Purpose Data Memory registers
are accessible in all banks, with the exception of the EEC register at address 40H, which is only
accessible in Bank 1. Switching between the different Data Memory banks is achieved by setting the
Bank Pointer to the correct value. The start address of the Data Memory is the address “00H”.
All microcontroller programs require an area of read/write memory where temporary data can be
stored and retrieved for use later. It is this area of RAM memory that is known as General Purpose
Data Memory. This area of Data Memory is fully accessible by the user program for both read and
write operations. By using the “SET [m].i” and “CLR [m].i” instructions individual bits can be set
or reset under program control giving the user a large range of flexibility for bit manipulation in the
Data Memory.
Special Function Registers
Most of the Special Function Register details will be described in the relevant functional section,
however several registers require a separate description in this section.
Special Purpose Data Memory